α- and β-amino acid hydroxyethylamino sulfonamides useful as retroviral protease inhibitors

ABSTRACT

α- and β-amino acid hydroxyethylamino sulfonamide compounds are effective as retroviral protease inhibitors, and in particular as inhibitors of HIV protease.

RELATED APPLICATION

This is a divisional of application Ser. No. 08/110,911 filed Aug. 24,1993, now U.S. Pat. No. 5,843,946, which is a continuation-in-part ofapplication Ser. No. 07/934,984, filed Aug. 25, 1992 now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to retroviral protease inhibitors and,more particularly, relates to novel compounds and a composition andmethod for inhibiting retroviral proteases. This invention, inparticular, relates to sulfonamide-containing hydroxyethylamine proteaseinhibitor compounds, a composition and method for inhibiting retorviralproteases such as human immunodeficiency virus (HIV) protease and fortreating a retroviral infection, e.g., an HIV infection. The subjectinvention also relates to processes for making such compounds as well asto intermediates useful in such processes.

2. Related Art

During the replication cycle of retroviruses, gag and gag-pol geneproducts are translated as proteins. These proteins are subsequentlyprocessed by a virally encoded protease (or proteinase) to yield viralenzymes and structural proteins of the virus core. Most commonly, thegag precursor proteins are processed into the core proteins and the polprecursor proteins are processed into the viral enzymes, e.g., reversetranscriptase and retroviral protease. It has been shown that correctprocessing of the precursor proteins by the retroviral protease isnecessary for assembly of infectious virons. For example, it has beenshown that frameshift mutations in the protease region of the pol geneof HIV prevents processing of the gag precursor protein. It has alsobeen shown through site-directed mutagenesis of an aspartic acid residuein the HIV protease that processing of the gag precursor protein isprevented. Thus, attempts have been made to inhibit viral replication byinhibiting the action of retroviral proteases.

Retroviral protease inhibition may involve a transition-state mimeticwhereby the retroviral protease is exposed to a mimetic compound whichbinds to the enzyme in competition with the gag and gag-pol proteins tothereby inhibit replication of structural proteins and, moreimportantly, the retroviral protease itself. In this manner, retroviralreplication proteases can be effectively inhibited.

Several classes of compounds have been proposed, particularly forinhibition of proteases, such as for inhibition of HIV protease. Suchcompounds include hydroxyethylamine isosteres and reduced amideisosteres. See, for example, EP O 346 847; EP O 342,541; Roberts et al,“Rational Design of Peptide-Based Proteinase Inhibitors, “Science, 248,358 (1990); and Erickson et al, “Design Activity, and 2.8 Å CrystalStructure of a C₂ Symmetric Inhibitor Complexed to HIV-1 Protease,”Science, 249, 527 (1990).

Several classes of compounds are known to be useful as inhibitors of theproteolytic enzyme renin. See, for example, U.S. No. 4,599,198; U.K.2,184,730; G.B. 2,209,752; EP O 264 795; G.B. 2,200,115 and U.S. SIRH725. Of these, G.B. 2,200,115, GB 2,209,752, EP O 264,795, U.S. SIRH725 and U.S. Pat. No. 4,599,198 disclose urea-containinghydroxyethylamine renin inhibitors. G.B. 2,200,115 also disclosessulfamoyl-containing hydroxyethylamine renin inhibitors, and EP 0264 795discloses certain sulfonamide-containing hydroxyethylamine renininhibitors. However, it is known that, although renin and HIV proteasesare both classified as aspartyl proteases, compounds which are effectiverenin inhibitors generally cannot be predicted to be effective HIVprotease inhibitors.

BRIEF DESCRIPTION OF THE INVENTION

The present invention is directed to virus inhibiting compounds andcompositions. More particularly, the present invention is directed toretroviral protease inhibiting compounds and compositions, to a methodof inhibiting retroviral proteases, to processes for preparing thecompounds and to intermediates useful in such processes. The subjectcompounds are characterized as sulfonamide-containing hydroxyethylamineinhibitor compounds.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, there is provided a retroviralprotease inhibiting compound of the formula:

or a pharmaceutically acceptable salt, prodrug or ester thereof wherein:

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteraralkoxycarbonyl, heteroaryloxycarbonyl, heteroaroyl, alkyl,alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl,heteroaryloxyalkyl, hydroxyalkyl, aminocarbonyl, aminoalkanoyl, andmono- and disubstituted aminocarbonyl and mono- and disubstitutedaminoalkanoyl radicals wherein the substituents are selected from alkyl,aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl,heterocycloalkyl, heterocycloalkyalkyl radicals, or where saidaminocarbonyl and aminoalkanoyl radicals are disubstituted, saidsubstituents along with the nitrogen atom to which they are attachedform a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen, radicals as defined for R³ or R″SO₂— wherein R″represents radicals as defined for R³; or R and R′ together with thenitrogen to which they are attached represent heterocycloalkyl andheteroaryl radicals;

R¹ represents hydrogen, —CH₂SO₂NH₂, —CH₂CO₂CH₃, —CO₂CH₃, —CONH₂,—CH₂C(O)NHCH₃, —C(CH₃)₂(SH), —C(CH₃)₂(SCH₃), —C(CH₃)₂(S[O]CH₃),—C(CH₃)₂(S[O]₂CH₃), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkylradicals, and amino acid side chains selected from asparagine, S-methylcysteine and the sulfoxide (SO) and sulfone (SO₂) derivatives thereof,isoleucine, allo-isoleucine, alanine, leucine, tert-leucine,phenylalanine, ornithine, histidine, norleucine, glutamine, threonine,glycine, allo-threonine, serine, O-alkyl serine, aspartic acid,beta-cyano alanine and valine side chains;

R¹′ and R¹″ independently represent hydrogen and radicals as defined forR¹, or one of R¹′ and R¹″, together with R¹ and the carbon atoms towhich R¹, R¹′ and R¹″ are attached, represent a cycloalkyl radical;

R² represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkylradicals, which radicals are optionally substituted with a groupselected from alkyl and halogen radials, —NO₂, —CN, —CF₃, —OR⁹ and —SR⁹,wherein R⁹ represents hydrogen and alkyl radicals, and halogen radicals;

R³ represents hydrogen, alkyl, haloalkyl, alkenyl, alkynyl,hydroxyalkyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl,heterocycloalkyl, heteroaryl, heterocycloalkylalkyl, aryl, aralkyl,heteroaralkyl, aminoalkyl and mono- and disubstituted aminoalkylradicals, wherein said substituents are selected from alkyl, aryl,aralyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl,heterocycloalkyl; and heterocycloalkylalkyl radicals, or in the case ofa disubstituted aminoalkyl radical, said substituents along with thenitrogen atom to which they are attached, form a heterocycloalkyl or aheteroaryl radical;

R⁴ represents radicals as defined by R³ except for hydrogen;

R⁶ represents hydrogen and alkyl radicals;

x represents 0, 1 or 2;

t represents either 0 or 1; and

Y represents O, S and NR¹⁵ wherein R¹⁵ represents hydrogen and radicalsas defined for R³.

A family of compounds of particular interest within Formula I arecompounds embraced by Formula II:

wherein:

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, alkyl,alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl,hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstitutedaminocarbonyl and mono- and disubstituted aminoalkanoyl radicals whereinthe substituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents hydrogen, —CH₂SO₂NH₂, —CH₂CO₂CH₃, —CO₂CH₃, —CONH₂,—CH₂C(O)NHCH₃, —C(CH₃)₂(SH), —C(CH₃)₂(SCH₃), —C(CH₃)₂(S[O]CH₃),—C(CH₃)₂(S[O]₂CH₃), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkylradicals, and amino acid side chains selected from asparagine, S-methylcysteine and the sulfoxide (SO) and sulfone (SO₂) derivatives thereof,isoleucine, allo-isoleucine, alanine, leucine, tert-leucine,phenylalanine, ornithine, histidine, norleucine, glutamine, threonine,glycine, allo-threonine, serine, O-methyl serine, aspartic acid,beta-cyano alanine and valine side chains;

R² represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkylradicals, which radicals are optionally substituted with a groupselected from alkyl and halogen radials, —NO₂, —C≡N, CF₃, —OR⁹, —SR⁹,wherein R⁹ represents hydrogen and alkyl radicals;

R³ represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl,alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl,heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl andmono- and disubstituted aminoalkyl radicals, wherein said substituentsare selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkylradicals, or in the case of a disubstituted aminoalkyl radical, saidsubstituents along with the nitrogen atom to which they are attached,form a heterocycloalkyl or a heteroaryl radical; and

R⁴ represents radicals as defined by R³.

A more preferred family of compounds within Formula II consists ofcompounds wherein:

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, alkyl,alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl,hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstitutedaminocarbonyl and mono- and disubstituted aminoalkanoyl radicals whereinthe substituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents CH₂C(O)NHCH₃, C(CH₃)₂(SCH₃), C(CH₃)₂(S[O]CH₃),C(CH₃)₂(S[O]₂CH₃), alkyl, alkenyl and alkynyl radicals, and amino acidside chains selected from the group consisting of asparagine, valine,threonine, allo-threonine, isoleucine, tert-leucine, S-methyl cysteineand the sulfone and sulfoxide derivatives thereof, alanine, andallo-isoleucine;

R² represents alkyl, cycloalkylalkyl and aralkyl radicals, whichradicals are optionally substituted with halogen radicals and radicalsrepresented by the formula —OR⁹ and —SR⁹ wherein R⁹ represents alkylradicals; and

R³ and R⁴ independently represent alkyl, alkenyl, alkoxyalkyl,cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl,aryl, aralkyl and heteroaralkyl radicals.

Of highest interest are compounds within Formula II wherein

R represents alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl,aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyland mono- and disubstituted aminoalkanoyl radicals wherein thesubstituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkylalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents CH₂C(O)NHCH₃, C(CH₃)₂(SCH₃), C(CH₃)₂(S[O]CH₃),C(CH₃)₂(S[O]₂CH₃), methyl, propargyl, t-butyl, isopropyl and sec-butylradicals, and amino acid side chains selected from the group consistingof asparagine, valine, S-methyl cysteine, allo-iso-leucine, iso-leucine,and beta-cyano alanine side chains;

R² represents CH₃SCH₂CH₂—, iso-butyl, n-butyl, benzyl, 4-fluorobenzyl,2-naphthylmethyl and cyclohexylmethyl radicals;

R³ represents isoamyl, n-butyl, isobutyl and cyclohexyl radicals; and

R⁴ represents phenyl, substituted phenyl and methyl radicals.

Another family of compounds of particular interest within Formula I arecompounds embraced by Formula III:

wherein:

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, alkyl,alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl,hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstitutedaminocarbonyl and mono- and disubstituted aminoalkanoyl radicals whereinthe substituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkylalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents hydrogen, —CH₂SO₂NH₂, —CH₂CO₂CH₃, —CO₂CH₃, —CONH₂,—CH₂C(O)NHCH₃, —C(CH₃)₂(SH), —C(CH₃)₂(SCH₃), —C(CH₃)₂(S[O]CH₃,—C(CH₃)₂(S[O]₂CH₃, alkyl, haloalkyl, alkenyl, alkynyl and cycloalkylradicals, and amino acid side chains selected from asparagine, S-methylcysteine and the sulfoxide (SO) and sulfone (SO₂) derivatives thereof,isoleucine, allo-isoleucine, alanine, leucine, tert-leucine,phenylalanine, ornithine, histidine, norleucine, glutamine, threonine,glycine, allo-threonine, serine, aspartic acid, beta-cyano alanine andvaline side chains;

R² represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkylradicals, which radicals are optionally substituted with a groupselected from alkyl and halogen radicals, —NO₂, —C≡N, CF₃, —OR⁹, —SR⁹,wherein R⁹ represents hydrogen and alkyl;

R³ represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl,alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl,heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl andmono- and disubstituted aminoalkyl radicals, wherein said substituentsare selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkylradicals, or in the case of a disubstituted aminoalkyl radical, saidsubstituents along with the nitrogen atom to which they are attached,form a heterocycloalkyl or a heteroaryl radical; and

R⁴ represents radicals as defined by R³.

A more preferred family of compounds within Formula III consists ofcompounds wherein

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, alkyl,alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl,hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstitutedaminocarbonyl and mono- and disubstituted aminoalkanoyl radicals whereinthe substituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkylalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents hydrogen, alkyl and alkenyl radicals, and amino acid sidechains selected from the group consisting of asparagine, valine,threonine, allo-threonine, isoleucine, tert-leucine, S-methyl cysteineand the sulfone and sulfoxide derivatives thereof, alanine, andallo-isoleucine;

R² represents alkyl, cycloalkylalkyl and aralkyl radicals, whichradicals are optionally substituted with halogen radicals and radicalsrepresented by the formula —OR⁹ and —SR⁹ wherein R⁹ represents hydrogenand alkyl and halogen radicals; and

R³ and R⁴ independently represent alkyl, alkenyl, alkoxyalkyl,cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl,aryl, aralkyl, heteroaryl and heteroaralkyl radicals.

Of highest interest are compounds within Formula III wherein

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl,aminocarbonyl, aminoalkanoyl, and mono- and disubstituted aminocarbonyland mono- and disubstituted aminoalkanoyl radicals wherein thesubstituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents hydrogen, methyl, propargyl, t-butyl, isopropyl andsec-butyl radicals, and amino acid side chains selected from the groupconsisting of asparagine, valine, S-methyl, cysteine, allo-iso-leucine,iso-leucine, threonine, serine, aspartic acid, beta-cyano alanine, andallo-threonine side chains;

R² represents CH₃SCH₂CH₂—, iso-butyl, n-butyl, benzyl, 4-fluorobenzyl,2-naphthylmethyl and cyclohexylmethyl radicals; and

R³ represents alkyl, cyclohexyl, isobutyl, isoamyl, and n-butylradicals; and

R⁴ represents methyl, phenyl and substituted phenyl radicals wherein thesubstituents are selected from halo, alkoxy, hydroxy, nitro and aminosubstituents.

Another family of compounds of particular interest within Formula I arecompounds embraced by Formula IV:

wherein:

R represents hydrogen, alkoxycarbonyl, aralkoxycarbonyl, alkylcarbonyl,cycloalkylcarbonyl, cycloalkylalkoxycarbonyl, cycloalkylalkanoyl,alkanoyl, aralkanoyl, aroyl, aryloxycarbonyl, aryloxycarbonylalkyl,aryloxyalkanoyl, heterocyclylcarbonyl, heterocyclyloxycarbonyl,heterocyclylalkanoyl, heterocyclylalkoxycarbonyl, heteroaralkanoyl,heteroaralkoxycarbonyl, heteroaryloxy-carbonyl, heteroaroyl, alkyl,alkenyl, cycloalkyl, aryl, aralkyl, aryloxyalkyl, heteroaryloxyalkyl,hydroxyalkyl, aminocarbonyl, aminoalkanoyl, and mono- and disubstitutedaminocarbonyl and mono- and disubstituted aminoalkanoyl radicals whereinthe substituents are selected from alkyl, aryl, aralkyl, cycloalkyl,cycloalkylalkyl, heteroaryl, heteroaralkyl, heterocycloalkyl,heterocycloalkyalkyl radicals, or where said aminoalkanoyl radical isdisubstituted, said substituents along with the nitrogen atom to whichthey are attached form a heterocycloalkyl or heteroaryl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached representheterocycloalkyl and heteroaryl radical;

R¹ represents hydrogen, —CH₂SO₂NH₂, —CH₂CO₂CH₃, —CO₂CH₃, —CONH₂,—CH₂C(O)NHCH₃, —C(CH₃)₂(SH), —C(CH₃)₂(SCH₃), —C(CH₃)₂(S[O]CH₃,—(CH₃)₂(S[O]₂CH₃), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkylradicals, and amino acid side chains selected from asparagine, S-methylcysteine and the sulfoxide (SO) and sulfone (SO₂) derivatives thereof,isoleucine, allo-isoleucine, alanine, leucine, tert-leucine,phenylalanine, ornithine, histidine, norleucine, glutamine, threonine,glycine, allo-threonine, serine, aspartic acid, beta-cyano alanine andvaline side chains;

R¹′ and R¹″ independently represent hydrogen and radicals as defined forR¹, or one of R¹′ and R¹″ together with R¹ and the carbon atoms to whichR¹, R¹′ and R¹″ are attached, represent a cycloalkyl radical;

R² represents alkyl, aryl, cycloalkyl, cycloalkylalkyl and aralkylradicals, which radicals are optionally substituted with a groupselected from alkyl and halogen radials, —NO₂, —C≡N, CF₃, —OR⁹ and —SR⁹,wherein R⁹ represents hydrogen and alkyl radicals;

R³ represents alkyl, haloalkyl, alkenyl, alkynyl, hydroxyalkyl,alkoxyalkyl, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heteroaryl,heterocycloalkylalkyl, aryl, aralkyl, heteroaralkyl, aminoalkyl andmono- and disubstituted aminoalkyl radicals, wherein said substituentsare selected from alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl,heteroaryl, heteroaralkyl, heterocycloalkyl, and heterocycloalkylalkylradicals, or in the case of a disubstituted aminoalkyl radical, saidsubstituents along with the nitrogen atom to which they are attached,form a heterocycloalkyl or a heteroaryl radical; and

R⁴ represents radicals as defined by R³.

A more preferred family of compounds within Formula IV consists ofcompounds wherein

R represents an arylalkanoyl, heteroaroyl, aryloxyalkanoyl,aryloxycarbonyl, alkanoyl, aminocarbonyl, mono-substitutedaminoalkanoyl, or disubstituted aminoalkanoyl, or mono- ordialkylaminocarbonyl radical;

R′ represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached represent aheterocycloalkyl or heteroaryl radical;

R¹, R¹′ and R¹″ independently represent hydrogen and alkyl radicalshaving from 1 to about 4 carbon atoms, alkenyl, alkynyl, aralkylradicals, and radicals represented by the formula —CH₂C(O)R″ or —C(O)R″wherein R″ represents R³⁸, —NR³⁸R³⁹ and OR³⁸ wherein R³⁸ and R³⁹independently represent hydrogen and alkyl radicals having from 1 toabout 4 carbon atoms;

R² represents alkyl, cycloalkylalkyl and aralkyl radicals, whichradicals are optionally substituted with halogen radicals and radicalsrepresented by the formula —OR⁹ and —SR⁹ wherein R⁹ represents hydrogenand alkyl radicals; and

R³ and R⁴ independently represent alkyl, alkenyl, alkoxyalkyl,cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl,aryl, aralkyl, heteroaryl and heteroaralkyl radicals.

Of highest interest are compounds of Formula IV wherein:

R represents an arylalkanoyl, aryloxycarbonyl, aryloxyalkanoyl,alkanoyl, aminocarbonyl, mono-substituted aminoalkanoyl, ordisubstituted aminoalkanoyl, or mono- or dialkylaminocarbonyl radical;

R′represents hydrogen and radicals as defined for R³ or R and R′together with the nitrogen to which they are attached represent aheterocycloalkyl or heteroaryl radical; p1 R¹, R¹′ and R¹″ independentlyrepresent hydrogen, methyl, ethyl, benzyl, phenylpropyl and propargylradicals;

R² represents CH₃SCH₂CH₂— iso-butyl, n-butyl, benzyl, 4-fluorobenzyl,2-naphthylmethyl and cyclohexylmethyl radicals;

R³ represents alkyl, cyclohexyl, isobutyl, isoamyl and n-butyl radicals;and

R⁴ represents methyl, phenyl and substituted phenyl radicals wherein thesubstituents are selected from halo, alkoxy, amino and nitrosubstituents.

As utilized herein, the term “alkyl”, alone or in combination, means astraight-chain or branched-chain alkyl radical containing from 1 toabout 10, preferably from 1 to about 8, carbon atoms. Examples of suchradicals include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,sec-butyl, tert-butyl, pentyl, iso-amyl, hexyl, octyl and the like. Theterm “alkenyl”, alone or in combination, means a straight-chain orbranched-chain hydrocarbon radial having one or more double bonds andcontaining from 2 to about 18 carbon atoms preferably from 2 to about 8carbon atoms. Examples of suitable alkenyl radicals include ethenyl,propenyl, alkyl, 1,4-butadienyl and the like. The term “alkynyl”, aloneor in combination, means a straight-chain hydrocarbon radical having oneor more triple bonds and containing from 2 to about 10 carbon atoms.Examples of alkynyl radicals include ethynyl, propynyl, (propargyl),butynyl and the like. The term “alkoxy”, alone or in combination, meansan alkyl ether radical wherein the term alkyl is as defined above.Examples of suitable alkyl ether radicals include methoxy, ethoxy,n-propoxy, isopropoxy, n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy andthe like. The term “cycloalkyl”, alone or in combination, means asaturated or partially saturated monocyclic, bicyclic or tricyclic alkylradical wherein each cyclic moiety contains from about 3 to about 8carbon atoms and is cyclic. The term “cycloalkylalkyl” means an alkylradical as defined above which is substituted by a cycloalkyl radicalcontaining from about 3 to about 8, preferably from about 3 to about 6,carbon atoms. Examples of such cycloalkyl radicals include cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl and the like. The term “aryl”, aloneor in combination, means a phenyl or naphthyl radical which optionallycarries one or more substituents selected from alkyl, alkoxy, halogen,hydroxy, amino, nitro, cyano, haloalkyl and the like, such as phenyl,p-tolyl, 4-methoxyphenyl, 4-(tert-butoxy)phenyl, 4-fluorophenyl,4-chlorophenyl, 4-hydroxyphenyl, 1-naphthyl, 2-naphthyl, and the like.The term “aralkyl”, alone or in combination, means an alkyl radical asdefined above in which one hydrogen atom is replaced by an aryl radicalas defined above, such as benzyl, 2-phenylethyl and the like. The term“aralkoxy carbonyl”, alone or in combination, means a radical of theformula —C(O)—O-aralkyl in which the term “aralkyl” has the significancegiven above. An example of an aralkoxycarbonyl radical isbenzyloxycarbonyl. The term “aryloxy” means a radical of the formulaaryl-O- in which the term aryl has the significance given above. Theterm “alkanoyl”, alone or in combination, means an acyl radical derivedfrom an alkanecarboxylic acid, examples of which include acetyl,propionyl, butyryl, valeryl, 4-methylvaleryl, and the like. The term“cycloalkylcarbonyl” means an acyl group derived from a monocyclic orbridged cycloalkanecarboxylic acid such as cyclopropanecarbonyl,cyclohexanecarbonyl, adamantanecarbonyl, and the like, or from abenz-fused monocyclic cycloalkanecarboxylic acid which is optionallysubstituted by, for example, alkanoylamino, such as1,2,3,4-tetrahydro-2-naphthoyl, 2-1,2,3,4-tetrahydro-2-naphthoyl. Theterm “aralkanoyl” means an acyl radical derived from an aryl-substitutedalkanecarboxylic acid such as phenylacetyl, 3-phenylpropionyl(hydrocinnamoyl), 4-phenylbutyryl, (2-naphthyl)acetyl,4-chlorohydrocinnamoyl, 4-aminohydrocinnamoyl, 4-methoxyhydrocinnamoyl,and the like. The term “aroyl” means an acyl radical derived from anaromatic carboxylic acid. Examples of such radicals include aromaticcarboxylic acids, an optionally substituted benzoic or naphthoic acidsuch as benzoyl, 4-chlorobenzoyl, 4-carboxybenzoyl,4-(benzyloxycarbonyl)benzoyl, 1-naphthoyl, 2-naphthoyl, 6-carboxy-2naphthoyl, 6-(benzyloxycarbonyl)-2-naphthoyl, 3-benzyloxy-2-naphthoyl,3-hydroxy-2-naphthoyl, 3-(benzyloxyformamido)-2-naphthoyl, and the like.The heterocyclyl or heterocycloalkyl portion of a heterocyclylcarbonyl,heterocyclyloxycarbonyl, heterocyclylalkoxycarbonyl, or heterocycloalkylgroup or the like is a saturated or partially unsaturated monocyclic,bicyclic or tricyclic heterocycle which contains one or more heteroatoms selected from nitrogen, oxygen and sulphur, which is optionallysubstituted on one or more carbon atoms by halogen, alkyl, alkoxy, oxo,and the like, and/or on a secondary nitrogen atom (i.e., —NH—) by alkyl,aralkoxycarbonyl, alkanoyl, phenyl or phenylalkyl or on a tertiarynitrogen atom (i.e. ═N—) by oxido and which is attached via a carbonatom. The heteroaryl portion of a heteroaroyl, heteroaryloxycarbonyl, ora heteroaralkoxy carboxyl group or the like is an aromatic monocyclic,bicyclic, or tricyclic heterocycle which contains the hetero atoms andis optionally substituted as defined above with respect to thedefinition of heterocyclyl. Examples of such heterocyclyl and heteroarylgroups are pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl,thiamorpholinyl, pyrrolyl, imidazolyl (e.g., imidazol 4-yl,1-benzyloxycarbonylimidazol-4-yl, etc.), pyrazolyl, pyridyl, pyrazinyl,pyrimidinyl, furyl, thienyl, triazolyl, oxazolyl, thiazolyl, indolyl(e.g., 2-indolyl, etc), quinolinyl, (e.g., 2-quinolinyl, 3-quinolinyl,1-oxido-2-quinolinyl, etc), isoquinolinyl (e.g., 1-isoquinolinyl,3-isoquinolinyl, etc.), tetrahydroquinolinyl (e.g.,1,2,3,4-tetrahydro-2-quinolyl, etc.), 1,2,3,4-tetrahydroisoquinolinyl(e.g., 1,2,3,4-tetrahydro-1-oxo-isoquinolinyl, etc.), quinoxalinyl,β-carbolinyl, 2-benzofurancarbonyl, 1-, 2-, 4- or 5-benzimidazolyl, andthe like. The term “cycloalkylalkoxycarbonyl” means an acyl groupderived from a cycloalkylalkoxycarboxylic acid of the formulacycloalkylalkyl—O—COOH wherein cycloalkylalkyl has the significancegiven above. The term “aryloxyalkanoyl” means an acyl radical of theformula aryl-O-alkanoyl wherein aryl and alkanoyl have the significancegiven above. The term “heterocyclyloxycarbonyl” means an acyl groupderived from heterocyclyl-O-COOH wherein heterocyclyl is as definedabove. The term “heterocyclylalkanoyl” is an acyl radical derived from aheterocyclyl-substituted alkane carboxylic acid wherein heterocyclyl hasthe significance given above. The term “heterocyclylalkoxycarbonyl”means an acyl radical derived from a heterocyclyl-substitutedalkane-O-COOH wherein heterocyclyl has the significance given above. Theterm “heteroaryloxycarbonyl” means an acyl radical derived from acarboylic acid represented by heteroaryl-O-COOH wherein heteroaryl hasthe significance given above. The term “aminocarbonyl” alone or incombination, means an amino-substituted carbonyl (carbamoyl) groupderived from an amino-substituted carboxylic acid wherein the aminogroup can be a primary, secondary or tertiary amino group containingsubstituents selected from hydrogen, and alkyl, aryl, aralkyl,cycloalkyl, cycloalkylalkyl radicals and the like. The term“aminoalkanoyl” means an acyl group derived from an amino-substitutedalkanecarboxylic acid wherein the amino group can be a primary,secondary or tertiary amino group containing substituents selected fromhydrogen, and alkyl, aryl, aralkyl, cycloalkyl, cycloalkylalkyl radicalsand the like. The term “halogen” means fluorine, chlorine, bromine oriodine. The term “haloalkyl” means an alkyl radical having thesignificance as defined above wherein one or more hydrogens are replacedwith a halogen. Examples of such haloalkyl radicals includechloromethyl, 1-bromoethyl, fluoromethyl, difluoromethyl,trifluoromethyl, 1,1,1-trifluorethyl and the like. The term “leavinggroup” generally refers to groups readily displaceable by a nucleophile,such as an amine, a thiol or an alcohol nucleophile. Such leaving groupsare well known in the art. Examples of such leaving groups include, butare not limited to, N-hydroxysuccinimide, N-hydroxybenzotriazole,halides, triflates, tosylates and the like. Preferred leaving groups areindicated herein where appropriate.

Procedures for preparing the compounds of Formula I are set forth below.It should be noted that the general procedure is shown as it relates topreparation of compounds having the specified stereochemistry, forexample, wherein the absolute stereochemistry about the hydroxyl groupis designated as (R). However, such procedures are generally applicableto those compounds of opposite configuration, e.g., where thestereochemistry about the hydroxyl group is (S). In addition, thecompounds having the (R) stereochemistry can be utilized to producethose having the (S) stereochemistry. For example, a compound having the(R) stereochemistry can be inverted to the (S) stereochemistry usingwell-known methods.

Preparation of Compounds of Formula I

The compounds of the present invention represented by Formula I abovecan be prepared utilizing the following general procedure. Thisprocedure is schematically shown in the following Schemes I and II:

An N-protected chloroketone derivative of an amino acid having theformula:

wherein P represents an amino protecting group, and R² is as definedabove, is reduced to the corresponding alcohol utilizing an appropriatereducing agent. Suitable amino protecting groups are well known in theart and include carbobenzoxy, t-butoxycarbonyl, and the like. Apreferred amino protecting group is carbobenzoxy. A preferredN-protected chloroketone is N-benzyloxycarbonyl-L-phenylalaninechloromethyl ketone. A preferred reducing agent is sodium borohydride.The reduction reaction is conducted at a temperature of from −10° C. toabout 25° C., preferably at about 0° C., in a suitable solvent systemsuch as, for example, tetrahydrofuran, and the like. The N-protectedchloroketones are commercially available, e.g., such as from Bachem,Inc., Torrance, Calif. Alternatively, the chloroketones can be preparedby the procedure set forth in S. J. Fittkau, J. Prakt. Chem., 315, 1037(1973), and subsequently N-protected utilizing procedures which are wellknown in the art.

The halo alcohol can be utilized directly, as described below, or,preferably, is then reacted, preferably at room temperature, with asuitable base in a suitable solvent system to produce an N-protectedamino epoxide of the formula:

wherein P and R² are as defined above. Suitable solvent systems forpreparing the amino epoxide include ethanol, methanol, isopropanol,tetrahydrofuran, dioxane, and the like including mixtures thereof.Suitable bases for producing the epoxide from the reduced chloroketoneinclude potassium hydroxide, sodium hydroxide, potassium t-butoxide, DBUand the like. A preferred base is potassium hydroxide.

Alternatively, a protected amino epoxide can be prepared, such as inco-owned and co-pending PCT patent application Ser. No. PCT/US93/04804which is incorporated herein by reference, starting with an L-amino acidwhich is reacted with a suitable amino-protecting group in a suitablesolvent to produce an amino-protected L-amino acid ester of the formula:

wherein P³ represents carboxy-protecting group, e.g., methyl, ethyl,benzyl, tertiary-butyl and the like; R² is as defined above; and P¹ andP² independently are selected from amino protecting groups, includingbut not limited to, arylalkyl, substituted arylalkyl, cycloalkenylalkyland substituted cycloalkenylalkyl, allyl, substituted allyl, acyl,alkoxycarbonyl, aralkoxycarbonyl and silyl. Examples of arylalkylinclude, but are not limited to benzyl, orthomethylbenzyl, trityl andbenzhydryl, which can be optionally substituted with halogen, alkyl ofC₁-C₈, alkoxy, hydroxy, nitro, alkylene, amino, alkylamino, acylaminoand acyl, or their salts, such as phosphonium and ammonium salts.Examples of aryl groups include phenyl, naphthalenyl, indanyl,anthracenyl, durenyl, 9-(9-phenylfluoroenyl) and phenanthrenyl,cycloalkenylalkyl or substituted cycloalkenylalkyl radicals containingcycloalkyls of C₆-C₁₀. Suitable acyl groups include carbobenzoxy,t-butoxycarbonyl, iso-butoxycarbonyl, benzoyl, substituted benzoyl,butyryl, acetyl, tri-fluoroacetyl, tri-chloroacetyl, phthaloyl and thelike.

Additionally, the P¹ and/or P² protecting groups can form a heterocyclicring with the nitrogen to which they are attached, for example,1,2-bis(methylene)benzene, phthalimidyl, succinimidyl, maleimidyl andthe like and where these heterocyclic groups can further includeadjoining aryl and cycloalkyl rings. In addition, the heterocyclicgroups can be mono-, di- or tri-substituted, e.g., nitrophthalimidyl.The term sily refers to a silicon atom optionally substituted by one ormore alkyl, aryl and aralkyl groups.

Suitable silyl protecting groups include, but are not limited to,trimethylsilyl, triethylsilyl, tri-isopropylsilyl,tert-butyldimethylsilyl, dimethylphenylsily,1,2-bis(dimethylsilyl)benzene, 1,2-bis(dimethylsilyl)ethane anddiphenylmethylsilyl. Silylation of the amine functions to provide mono-or bis-disilylamine can provide derivatives of the aminoalcohol, aminoacid, amino acid esters and amino acid amide. In the case of aminoacids, amino acid esters and amino acid amides, reduction of thecarbonyl function provides the required mono- or bis-silyl aminoalcohol.Silylation of the aminoalcohol can lead to the N,N,O-tri-silyderivatives. Removal of the silyl function from the silyl ether functionis readily accomplished by treatment with, for example, a metalhydroxide or ammonium fluoride reagent, either as a discrete reactionstep or in situ during the preparation of the amino aldehyde reagent.Suitable silylating agents are, for example, trimethylsilyl chloride,tert-butydimethylsilyl chloride, phenyldimethylsilyl chloride,diphenylmethylsilyl chloride or their combination products withimidazole or DMF. Methods for silylation of amines and removal of silylprotecting groups are well known to those skilled in the art. Methods ofpreparation of these amine derivatives from corresponding amino acids,amino acid amides or amino acid esters are also well known to thoseskilled in the art of organic chemistry including amino acid/amino acidester or aminoalcohol chemistry.

Preferably P¹ and P² are independently selected from aralkyl andsubstituted aralkyl. More preferably, each of P¹ and P² is benzyl.

The amino-protected L-amino acid ester is then reduced, to thecorresponding alcohol. For example, the amino-protected L-amino acidester can be reduced with diisobutylaluminum hydride at −78° C. in asuitable solvent such as toluene. Preferred reducing agents includelithium aluminum hydride, lithium borohydride, sodium borohydride,borane, lithium tri-terbutoxyaluminum hydride, borane/THF complex. Mostpreferably, the reducing agent is diisobutylaluminum hydride (DiBAL-H)in toluene. The resulting alcohol is then converted, for example, by wayof a Swern oxidation, to the corresponding aldehyde of the formula:

wherein P¹, P² and R² are as defined above. Thus, a dichloromethanesolution of the alcohol is added to a cooled (−75 to −68° C.) solutionof oxalyl choride in dichloromethane and DMSO in dichloromethane andstirred for 35 minutes.

Acceptable oxidizing reagents include, for example, sulfurtrioxide-pyridine complex and DMSO, oxalyl chloride and DMSO, acetylchloride or anhydride and DMSO, trifluoroacetyl chloride or anhydrideand DMSO, methanesulfonyl chloride and DMSO ortetrahydrothiaphene-S-oxide, toluenesulfonyl bromide and DMSO,trifluoromethanesulfonyl anhydride (triflic anhydride) and DMSO,phosphorus pentachloride and DMSO, dimethylphosphoryl chloride and DMSOand isobutylchloroformate and DMSO. The oxidation conditions reported byReetz et al [Agnew Chem., 99, p. 1186, (1987)], Angew Chem. Int. Ed.Engl., 26, p. 1141, 1987) employed oxalyl chloride and DMSO at −78° C.

The preferred oxidation method described in this invention is sulfurtrioxide pyridine complex, triethylamine and DMSO at room temperature.This system provides excellent yields of the desired chiral protectedamino aldehyde usable without the need for purification e.g., the needto purify kilograms of intermediates by chromatography is eliminated andlarge scale operations are made less hazardous. Reaction at roomtemperature also eliminated the need for the use of low temperaturereactor which makes the process more suitable for commercial production.

The reaction may be carried out under and inert atmosphere such asnitrogen or argon, or normal or dry air, under atmospheric pressure orin a sealed reaction vessel under positive pressure. Preferred is anitrogen atmosphere. Alternative amine bases include, for example,tri-butyl amine, tri-isopropyl amine, N-methylpiperidine, N-methylmorpholine, azabicyclononane, diisopropylethylamine,2,2,6,6-tetramethylpiperidine, N,N-dimethylaminopyridine, or mixtures ofthese bases. Triethylamine is a preferred base. Alternatives to pureDMSO as solvent include mixtures of DMSO with non-protic or halogenatedsolvents such as tetrahydrofuran, ethyl acetate, toluene, xylene,dichloromethane, ethylene dichloride and the like. Dipolar aproticco-solvents include acetonitrile, dimethylformamide, dimethylacetamide,acetamide, tetramethyl urea and its cyclic analog, N-methylpyrrolidone,sulfolane and the like. Rather than N,N-dibenzylphenylalaninol as thealdehyde precursor, the phenylalaninol derivatives discussed above canbe used to provide the corresponding N-monosubstituted [either P¹ orP²=H] or N,N-disubstituted aldehyde.

In addition, hydride reduction of an amide or ester derivative of thecorresponding alkyl, benzyl or cycloalkenyl nitrogen protectedphenylalanine, substituted phenylalanine or cycloalkyl analog ofphenylalanine derivative can be carried out to provide the aldehydes.Hydride transfer is an additional method of aldehyde synthesis underconditions where aldehyde condensations are avoided, cf, OppenauerOxidation.

The aldehydes of this process can also be prepared by methods ofreducing protected phenylalanine and phenylalanine analogs or theiramide or ester derivatives by, e.g., sodium amalgam with HCl in ethanolor lithium or sodium or potassium or calcium in ammonia. The reactiontemperature may be from about −20° C. to about 45° C., and preferablyfrom about 5° C. to about 25° C. Two additional methods of obtaining thenitrogen protected aldehyde include oxidation of the correspondingalcohol with bleach in the presence of a catalytic amount of2,2,6,6-tetramethyl-1-pyridyloxy free radical. In a second method,oxidation of the alcohol to the aldehyde is accomplished by a catalyticamount of tetrapropylammonium perruthenate in the presence ofN-methylmorpholine-N-oxide.

Alternatively, an acid chloride derivative of a protected phenylalanineor phenylalanine derivative as disclosed above can be reduced withhydrogen and a catalyst such as Pd on barium carbonate or bariumsulphate, with or without an additional catalyst moderating agent suchas sulfur or a thiol (Rosenmund Reduction).

The aldehyde resulting from the Swern oxidation is then reacted with ahalomethyllithium reagent, which reagent is generated in situ byreacting an alkyllithium or arylithium compound with a dihalomethanerepresented by the formula X¹CH₂X² wherein X¹ and X² independentlyrepresent I, Br or Cl. For example, a solution of the aldehyde andchloroiodomethane in THF is cooled to −78° C. and a solution ofn-butyllithium in hexane is added. The resulting produce is a mixture ofdiastereomers of the corresponding amino-protected epoxides of theformulas:

The diastereomers can be separated e.g., by chromatography, or,alternatively, once reacted in subsequent steps the diastereomericproducts can be separated. For compounds having the (S) stereochemistry,a D-amino acid can be utilized in place of the L-amino acid.

The addition of chloromethylithium or bromomethylithium to a chiralamino aldehyde is highly diastereoselective. Preferably, thechloromethyllithium or bromomethylithium is generated in-situ from thereaction of the dihalomethane n-butyllithium. Acceptable methyleneatinghalomethanes include chloroiodomethane, bromochloromethane,dibromomethane, diiodomethane, bromofluoromethane and the like. Thesulfonate ester of the addition product of, for example, hydrogenbromide to formaldehyde is also a methyleneating agent. Tetrahydrofuranis the preferred solvent, however alternative solvents such as toluene,dimethoxyethane, ethylene dichloride, methylene chloride can be used aspure solvents or as a mixture. Dipolar aprotic solvents such asacetonitrile, DMF, N-methylpyrrolidone are useful as solvents or as partof a solvent mixture. The reaction can be carried out under an inertatmosphere such as nitrogen or argon. For n-butyl lithium can besubstituted other organometalic reagents reagents such as methyllithium,tert-butyl lithium, sec-butyl lithium, phenyllithium, phenyl sodium andthe like. The reaction can be carried out at temperatures of betweenabout −80° C. to 0° C. but preferably between about −80° C. to −20° C.The most preferred reaction temperatures are between −40° C. to −15° C.Reagents can be added singly but multiple additions are preferred incertain conditions. The preferred pressure of the reaction isatmospheric however a positive pressure is valuable under certainconditions such as a high humidity environment.

Alternative methods of conversion to the epoxides of this inventioninclude substitution of other charged methylenation precurser speciesfollowed by their treatment with base to form the analogous anion.Examples of these species include trimethylsulfoxonium tosylate ortriflate, tetramethylammonium halide, methyldiphenylsulfoxonium halidewherein halide is chloride, bromide or iodide.

The conversion of the aldehydes of this invention into their epoxidederivative can also be carried out in multiple steps. For example, theaddition of the anion of thioanisole prepared from, for example, a butylor aryl lithium reagent, to the protected aminoaldehyde, oxidation ofthe resulting protected aminosulfide alcohol with well known oxidizingagents such as hydrogen peroxide, tert-butyl hypochlorite, bleach orsodium periodate to give a sulfoxide. Alkylation or the sulfoxide with,for example, methyl iodide or bromide, methyl tosylate, methyl mesylate,methyl triflate, ethyl bromide, isopropyl bromide, benzyl chloride orthe like, in the presence of an organic or inorganic base Alternatively,the protected aminosulfide alcohol can be alkylated with, for example,the alkylating agents above, to provide a sulfonium salts that aresubsequently converted into the subject epoxides with tert-amine ormineral bases.

The desired epoxides formed, using most preferred conditions,diastereoselectively in ratio amounts of at least about 85:15 ratio(S:R). The product can be purified by chromatography to give thediastereomerically and enantiomerically pure product but it is moreconveniently used directly without purification to prepare retroviralprotease inhibitors. The foregoing process is applicable to mixtures ofoptical isomers as well as resolved compounds. If a particular opticalisomer is desired, it can be selected by the choice of startingmaterial, e.g., L-phenylalanine, D-phenylalanine, L-phenylalaninol,D-phenylalaninol, D-hexahydrophenylalaninol and the like, or resolutioncan occur at intermediate or final steps. Chiral auxiliaries such as oneor two equivilants of camphor sulfonic acid, citric acid, camphoricacid, 2-methoxyphenylacetic acid and the like can be used to form salts,esters or amides of the compounds of this invention. These compounds orderivatives can be crystallized or separated chromatographically usingeither a chiral or achiral column as is well known to those skilled inthe art.

The amino epoxide is then reacted, in a suitable solvent system, with anequal amount, or preferably an excess of, a desired amino of theformula:

R³NH₂

wherein R³ is hydrogen or is as defined above. The reaction can beconducted over a wide range of temperatures, e.g., from about 10° C. toabout 100° C., but is preferably, but not necessarily, conducted at atemperature at which the solvent begins to reflux. Suitable solventsystems include protic, non-protic and dipolar aprotic organic solventssuch as, for example, those wherein the solvent is an alcohol, such asmethanol, ethanol, isopropanol, and the like, ethers such astetrahydrofuran, dioxane and the like, and toluene,N,N-dimethylformamide, dimethyl sulfoxide, and mixtures thereof. Apreferred solvent is isopropanol. Exemplary amines corresponding to theformula R³NH₂ include benzyl amine, isobutylamine, n-butyl amine,isopentyl amine, isoamylamine, cyclohexanemethyl amine, naphthylenemethyl amine and the like. The resulting product is a 3-(N-protectedamino)-3-(R²)-1-(NHR³)-propan-2-ol derivative (hereinafter referred toas an amino alcohol) can be represented by the formulas:

wherein P, P¹, P², R² and R³ are as described above. Alternatively, ahaloalcohol can be utilized in place of the amino epoxide.

The amino alcohol defined above is then reacted in a suitable solventwith a sulfonyl chloride (R⁴SO₂Cl) or sulfonyl anhydride in the presenceof an acid scavenger. Suitable solvents in which the reaction can beconducted include methylene chloride, tetrahydrofuran. Suitable acidscavengers include triethylamine, pyridine. Preferred sulfonyl chloridesare methanesulfonyl chloride and benzenesulfonyl chloride. The resultingsulfonamide derivative can be represented, depending on the epoxideutilized by the formulas

wherein P, P¹, P², R², R³ and R⁴ are as defined above. Theseintermediates are useful for preparing inhibitor compounds of thepresent invention and are also active inhibitors of retroviralproteases.

The sulfonyl halides of the formula R⁴SO₂X can be prepared by thereaction of a suitable Grignard or alkyl lithium reagent with sulfurylchloride, or sulfur dioxide followed by oxidation with a halogen,preferably chlorine. Also, thiols may be oxidized to sulfonyl chloridesusing chlorine in the presence of water under carefully controlledconditions. Additionally, sulfonic acids may be converted to sulfonylhalides using reagents such as PCl₅, and also to anhydrides usingsuitable dehydrating reagents. The sulfonic acids may in turn beprepared using procedures well known in the art. Such sulfonic acids arealso commercially available. In place of the sulfonyl halides, sulfinylhalides (R⁴SOX) or sulfenyl halides (R⁴SX) can be utilized to preparecompounds wherein the —SO₂— moiety is replaced by an —SO— or —S— moiety,respectively.

Following preparation of the sulfonamide derivative, the aminoprotecting group P or P¹ and P² amino protecting groups are removedunder conditions which will not affect the remaining portion of themolecule. These methods are well known in the art and include acidhydrolysis, hydrogenolysis and the like. A preferred method involvesremoval of the protecting group, e.g., removal of a carbobenzoxy group,by hydrogenolysis utilizing palladium on carbon in a suitable solventsystem such as an alcohol, acetic acid, and the like or mixturesthereof. Where the protecting group is a t-butoxycarbonyl group, it canbe removed utilizing an inorganic or organic acid, e.g., HCl ortrifluoroacetic acid, in a suitable solvent system, e.g., dioxane ormethylene chloride. The resulting product is the amine salt derivative.Following neutralization of the salt, the amine is then reacted with anamino acid or corresponding derivative thereof represented by theformula (PN[CR¹′ R¹″]_(t) CH(R¹)COOH) where t, R¹, R¹′ and R¹″ are asdefined above, to produce the antiviral compounds of the presentinvention having the formula:

wherein t, P, R¹, R¹′, R¹″, R², R³ and R⁴ are as defined above.Preferred protecting groups in this instance are a benzyloxycarbonylgroup or a t-butoxycarbonyl group. Where the amine is reacted with aderivative of an amino acid, e.g., when t=1 and R¹′ and R¹″ are both H,so that the amino acid is a β-amino acid, such β-amino acids can beprepared according to the procedure set forth in a copendingapplication, U.S. Ser. No. 07/345,808. Where t is 1, one of R¹′ and R¹″is H and R¹ is hydrogen so that the amino acid is a homo-β-amino acid,such homo-β-amino acids can be prepared by the procedure set forth in acopending application, U.S. Ser. No. 07/853,561. Where t is 0 and R¹ isalkyl, alkenyl, alkynyl, cycloalkyl, —CH₂SO₂NH₂, —CH₂CO₂CH₃, —CO₂CH₃,—CONH₂, —CH₂C(O)NHCH₃, —C(CH₃)₂(SH), —C(CH₃)₂(SCH₃), —C(CH₃)₂[S(O)CH₃],—C(CH₃)₂[S(O₂)CH₃], or an amino acid side chain, such materials are wellknown and many are commercially available from Sigma-Aldrich.

The N-protecting group can be subsequently removed, if desired,utilizing the procedures described above, and then reacted with acarboxylate represented by the formula:

wherein R is as defined above and L is an appropriate leaving group suchas a halide. Preferably, where R¹ is a side chain of a naturallyoccurring α-amino acid, R is a 2-quinoline carbonyl group derived fromN-hydroxysuccinimide-2-quinoline carboxylate, i.e., L is hydroxysuccinimide. A solution of the free amine (or amine acetate salt) andabout 1.0 equivalent of the carboxylate are mixed in an appropriatesolvent system and optionally treated with up to five equivalents of abase such as, for example, N-methylmorpholine, at about roomtemperature. Appropriate solvent systems include tetrahydrofuran,methylene chloride or N,N-dimethylformamide, and the like, includingmixtures thereof.

Alternatively, the protected amino alcohol from the epoxide opening canbe further protected at the newly introduced amino group with aprotecting group P′ which is not removed when the first protecting P isremoved. One skilled in the art can choose appropriate combinations of Pand P′. One suitable choice is when P is Cbz and P′ is Boc. Theresulting compound represented by the formula:

can be carried through the remainder of the synthesis to provide acompound of the formula:

and the new protecting group P′ is selectively removed, and followingdeprotection, the resulting amine reacted to form the sulfonamidederivative as described above. This selective deprotection andconversion to the sulfonamide can be accomplished at either the end ofthe synthesis or at any appropriate intermediate step if desired.

In place of the sulfonyl halides, sulfinyl halides (RSOCl) and sulfenylhalides (RSCl) can be utilized to prepare compounds wherein the —SO₂—moiey is replaced by —SO— or —S—, respectively.

It is contemplated that for preparing compounds of the Formulas havingR⁶, the compounds can be prepared following the procedure set forthabove and, prior to coupling the sulfonamide derivative or analogthereof, e.g. coupling to the amino acid PNH(CH₂)_(t)CH(R¹)COOH, carriedthrough a procedure referred to in the art as reductive amination. Thus,a sodium cyanoborohydride and an appropriate aldehyde or ketone can bereacted with the sulfonamide derivative compound or appropriate analogat room temperature in order to reductively aminate any of the compoundsof Formulas I-IV. It is also contemplated that where R³ of the aminoalcohol intermediate is hydrogen, the inhibitor compounds of the presentinvention wherein R³ is alkyl, or other substituents wherein the α-Ccontains at least one hydrogen, can be prepared through reductiveamination of the final product of the reaction between the amino alcoholand the amine or at any other stage of the synthesis for preparing theinhibitor compounds.

Contemplated equivalents of the general formulas set forth above for theantiviral compounds and derivatives as well as the intermediates arecompounds otherwise corresponding thereto and having the same generalproperties, such as tautomers thereof as well as compounds, wherein oneor more of the various R groups are simple variations of thesubstituents as defined therein, e.g., wherein R is a higher alkyl groupthan that indicated. In addition, where a substituent is designated as,or can be, a hydrogen, the exact chemical nature of a substituent whichis other than hydrogen at that position, e.g., a hydrocarbyl radical ora halogen, hydroxy, amino and the like functional group, is not criticalso long as it does not adversely affect the overall activity and/orsynthesis procedure.

The chemical reactions described above are generally disclosed in termsof their broadest application to the preparation of the compounds ofthis invention. Occasionally, the reactions may not be applicable asdescribed to each compound included within the disclosed scope. Thecompounds for which this occurs will be readily recognized by thoseskilled in the art. In all such cases, either the reactions can besuccessfully performed by conventional modifications known to thoseskilled in the art, e.g., by appropriate protection of interferinggroups, by changing to alternative conventional reagents, by routinemodification of reaction conditions, and the like, or other reactionsdisclosed herein or otherwise conventional, will be applicable to thepreparation of the corresponding compounds of this invention. In allpreparative methods, all starting materials are known or readilypreparable from known starting materials.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following preferred specific embodiments are,therefore, to be construed as merely illustrative, and not limitative ofthe remainder of the disclosure in any way whatsoever.

All reagents were used as received without purification. All proton andcarbon NMR spectra were obtained on either a Varian VXR-300 or VXR-400nuclear magnetic resonance spectrometer.

The following Examples 1 through 9 illustrate preparation ofintermediates. These intermediates are useful in preparing the inhibitorcompounds of the present invention as illustrated in Examples 10-16. Inaddition, the intermediates of Examples 2-6 are also retroviral proteaseinhibitors and inhibit, in particular, HIV protease.

Example 1A

Preparation ofN[3(S)-benzyloxycarbonylamino-2(R)-hydroxy-4-phenylbutyl]-N-isoamylamine

Part A:

To a solution of 75.0 g (0.226 mol) ofN-benzyloxycarbonyl-L-phenylalanine chloromethyl ketone in a mixture of807 mL of methanol and 807 mL of tetrahydrofuran at −2° C., was added13.17 g (0.348 mol, 1.54 equiv.) of solid sodium borohydride over onehundred minutes. The solvents were removed under reduced pressure at 40°C. and the residue dissolved in ethyl acetate (approx. 1 L). Thesolution was washed sequentially with 1M potassium hydrogen sulfate,saturated sodium bicarbonate and then saturated sodium chloridesolutions. After drying over anhydrous magnesium sulfate and filtering,the solution was removed under reduced pressure. To the resulting oilwas added hexane (approx. 1 L) and the mixture was warmed to 60° C. withswirling. After cooling to room temperature, the solids were collectedand washed with 2 L of hexane. The resulting solid was recrystallizedfrom hot ethyl acetate and hexane to afford 32.3 g (43% yield) ofN-benzyloxycarbonyl-3(S)-amino-1-chloro-4-phenyl-2(S)-butanol, mp150-151° C. and M+Li⁺=340.

Part B:

To a solution of 6.52 g (0.116 mol, 1.2 equiv.) of potassium hydroxidein 968 mL of absolute ethanol at room temperature, was added 32.3 g(0.097 mol) of N-CBZ-3(S)-amino-1-chloro-4-phenyl-2(S)-butanol. Afterstirring for fifteen minutes, the solvent was removed under reducedpressure and the solids dissolved in methylene chloride. After washingwith water, drying over magnesium sulfate, filtering and stripping, oneobtains 27.9 g of a white solid. Recrystallization from hot ethylacetate and hexane afforded 22.3 g (77% yield) ofN-benzyloxycarbonyl-3(S)-amino-1,2(S)-epoxy-4-phenylbutane, mp 102-103°C. and MH⁺ 298.

Part C:

A solution of N-benzyloxycarbonyl3(S)-amino-1,2-(S)-epoxy-4-phenylbutane (1.00 g, 3.36 mmol) andisoamylamine (4.90 g, 67.2 mmol, 20 equiv.) in 10 mL of isopropylalcohol was heated to reflux for 1.5 hours. The solution was cooled toroom temperature, concentrated in vacuo and then poured into 100 mL ofstirring hexane whereupon the product crystallized from solution. Theproduct was isolated by filtration and air dried to give 1.18 g, 95% ofN=[[3(S)-phenylmethylcarbamoyl)amino-2(R)-hydroxy-4-phenylbutyl]N-[(3-methylbutyl)]aminomp 108.0-109.5° C., MH⁺ m/z=371.

Example 1B

Preparation of N,N-dibenzyl-3(S)-amino-1,2-(S)-epoxy-4-phenylbutane

Step A:

A solution of L-phenylalanine (50.0 g, 0.302 mol), sodium hydroxide(24.2 g, 0.605 mol) and potassium carbonate (83.6 g, 0.605 mol) in water(500 ml) was heated to 97° C. Benzyl bromide (108.5 ml, 0.912 mol) thenslowly added (addition time ˜25 min). The mixture was then stirred at97° C. for 30 minutes. The solution was cooled to room temperature andextracted with toluene (2×250 ml). The combined organic layers were thenwashed with water, brine, dried over magnesium sulfate, filtered andconcentrated to give an oil product. The crude product was then used inthe next step without purification.

Step B:

The crude benzylated product of the above step was dissolved in toluene(750 ml) and cooled to −55° C. A 1.5 M solution of DIBAL-H in toluene(443.9 ml, 0.666 mol) was then added at a rate to maintain thetemperature between −55° to −50° C. (addition time—1 hour). The mixturewas stirred for 20 minutes at −55° C. The reaction was quenched at −55°C. by the slow addition of methanol (37 ml). The cold solution was thenpoured into cold (5° C.) 1.5 N HCl solution (1.8 L). The precipitatedsolid (approx. 138 g) was filtered off and washed with toluene. Thesolid material was suspended in a mixture of toluene (400 ml) and water(100 ml). The mixture was cooled to 5° C., treated with 2.5 N NaOH (186ml) and then stirred at room temperature until the solid was dissolved.The toluene layer was separated from the aqueous phase and washed withwater and brine, dried over magnesium sulfate, filtered and concentratedto a volume of 75 ml (89 g). Ethyl acetate (25 ml) and hexane (25 ml)were then added to the residue upon which the alcohol product began tocrystallize. After 30 min., an additional 50 ml hexane was added topromote further crystallization. The solid was filtered off and washedwith 50 ml hexane to give approximately 35 g of material. A second cropof material could be isolated by refiltering the mother liquor. Thesolids were combined and recrystallized from ethyl acetate (20 ml) andhexane (30 ml) to give in 2 crops, approximately 40 g (40% fromL-phenylalanine) of analytically pure alcohol product. The motherliquors were combined and concentrated (34 g). The residue was treatedwith ethyl acetate and hexane which provided an additional 7 g (∞7%yield) of slightly impure solid product. Further optimization in therecovery from the mother liquor is probable.

Alternatively, the alcohol was prepared from L-phenylalaninol.L-phenylalaninol (176.6 g, 1.168 mol) was added to a stirred solution ofpotassium carbonate (484.6 g, 3.506 mol) in 710 mL of water. The mixturewas heated to 65° C. under a nitrogen atmosphere. A solution of benzylbromide (400 g, 2.339 mol) in 3A ethanol (305 mL) was added at a ratethat maintained the temperature between 60-68° C. The biphasic solutionwas stirred at 65° C. for 55 min and then allowed to cool to 10° C. withvigorous stirring. The oily product solidified into small granules. Theproduct was diluted with 2.0 L of tap water and stirred for 5 minutes todissolve the inorganic by products. The product was isolated byfiltration under reduced pressure and washed with water until the pH is7. The crude product obtained was air dried overnite to give a semi-drysolid (407 g) which was recrystallized from 1.1 L of ethylacetate/heptane (1:10 by volume). The product was isolated by filtration(at −8° C.), washed with 1.6 L of cold (−10° C.) ethyl acetate/heptane(1:10 by volume) and air-dried to give 339 g (88% yield) ofβS-2-[Bis(phenylmethyl)amino]benzene-propanol, mp 71.5-73.0° C. Moreproduct can be obtained from the mother liquor if necessary. The otheranalytical characterization was identical to compound prepared asdescribed above.

Step C:

A solution of oxalyl chloride (8.4 ml, 0.096 mol) in dichloromethane(240 ml) was cooled to −74° C. A solution of DMSO (12.0 ml, 0.155 mol)in dichloromethane (50 ml) was then slowly added at a rate to maintainthe temperature at −74° C. (addition time ˜1.25 hr). The mixture wasstirred for 5 min. followed by addition of a solution of the alcohol(0.074 mol) in 100 ml of dichloromethane (addition time −20 min., temp.−75° C. to −68° C.). The solution was stirred at −78° C. for 35 minutes.Triethylamine (41.2 ml, 0.295 mol) was then added over 10 min. (temp.−78° to −68° C.) upon which the ammonium salt precipitated. The coldmixture was stirred for 30 min. and then water (225 ml) was added. Thedichloromethane layer was separated from the aqueous phase and washedwith water, brine, dried over magnesium sulfate, filtered andconcentrated. The residue was diluted with ethyl acetate and hexane andthen filtered to further remove the ammonium salt. The filtrate wasconcentrated to give the desired aldehyde product. The aldehyde wascarried on to the next step without purification.

Temperatures higher than −70° C. have been reported in the literaturefor the Swern oxidation. Other Swern modifications and alternatives tothe Swern oxidations are also possible.

Alternatively, the aldehyde was prepared as follows. (200 g, 0.604 mol)was dissolved in triethylamine (300 mL, 2.15 mol). The mixture wascooled to 12° C. and a solution of sulfur trioxide/pyridine complex (380g, 2.39 mol) in DMSO (1.6 L) was added at a rate to maintain thetemperature between 8-17° C. (addition time—1.0 h). The solution wasstirred at ambient temperature under a nitrogen atmosphere for 1.5 hourat which time the reaction was complete by TLC analysis (33% ethylacetate/hexane, silica gel). The reaction mixture was cooled with icewater and quenced with 1.6 L of cold water (10-15° C.) over 45 minutes.The resultant solution was extracted with ethyl acetate (2.0 L), washedwith 5% citric acid (2.0 L), and brine (2.2 L), dried over MgSO₄ (280 g)and filtered. The solvent was removed on a rotary evaporator at 35-40°C. and then dried over vaccuum to give 198.8 g ofαS-[Bis-(phenylmethyl)amino]-benzenepropanaldehyde as a pale yellow oil(99.9%). The crude product obtained was pure enough to be used directlyin the next step without purification. The analytical data of thecompound were consistent with the published literature. [α]_(D)25=−92.9°(c 1.87, CH₂Cl₂); ¹H NMR (400 MHz, CDCl₃) δ, 2.94 and 3.15 (ABX-System,2H, J_(AB)=13.9 Hz, J_(AX)=7.3 Hz and J_(BX)=6.2 Hz), 3.56 (t, 1H, 7.1Hz), 3.69 and 3.82 (AB-System, 4H, J_(AB)=13.7 Hz), 7.25 (m, 15 H) and9.72 (s, 1H); HRMS calcd for (M+1) C₂₃H₂₄NO 330.450, found: 330.1836.Anal. Calcd. for C₂₃H₂₃ON: C, 83.86; H, 7.04; N, 4.25. Found: C, 83.64;H, 7.42; N, 4.19. HPLC on chiral stationary phase:(S,S) Pirkle-Whelk-O 1column (250×4.6 mm I.D.), mobile phase: hexane/isopropanol (99.5:0.5,v/v), flow-rate: 1.5 ml/min, detection with UV detector at 210 nm.Retention time of the desired S-isomer: 8.75 min., retention time of theR-enantiomer 10.62 min.

Step D:

A solution of αS-[Bis(phenylmethyl)amino] benzene-propanaldehyde (191.7g, 0.58 mol) and chloroiodomethane (56.4 mL, 0.77 mol) intetrahydrofuran (1.8 L) was cooled to −30 to −35° C. (colder temperaturesuch as −70° C. also worked well but warmer temperatures are morereadily achieved in large scale operations) in a stainless steel reactorunder a nitrogen atmosphere. A solution of n-butyllithium in hexane (1.6M, 365 mL, 0.58 mol) was then added at a rate that maintained thetemperature below −25° C. After addition the mixture was stirred at −30to −35° C. for 10 minutes. More additions of reagents were carried outin the following manner: (1) additional chloroiodomethane (17 mL) wasadded, followed by n-butyllithium (110 mL) at <−25° C. After additionthe mixture was stirred at −30 to −35° C. for 10 minutes. This wasrepeated once. (2) Additional chloroiodomethane.(8.5 mL, 0.11 mol) wasadded, followed by n-butyllithium (55 mL, 0.088 mol) at <−25° C. Afteraddition, the mixture was stirred at −30 to −35° C. for 10 minutes. Thiswas repeated 5 times. (3) Additional chloroiodomethane (8.5 mL, 0.11mol) was added, followed by n-butyllithium (37 mL, 0.059 mol) at <−25°C. After addition, the mixture was stirred at −30 to −35° C. for 10minutes. This was repeated once. The external cooling was stopped andthe mixture warmed to ambient temp. over 4 to 16 hours when TLC (silicagel, 20% ethyl acetate/hexane) indicated that the reaction wascompleted. The reaction mixture was cooled to 10° C. and quenched with1452 g of 16% ammonium chloride solution prepared by dissolving 232 g ofammonium chloride in 1220 mL of water), keeping the temperature below23° C. The mixture was stirred for 10 minutes and the organic andaqueous layer were separated. The aqueous phase was extracted with ethylacetate (2×500 mL). The ethyl acetate layer was combined with thetetrahydrofuran layer. The combined solution was dried over magnesiumsulfate (220 g), filtered and concentrated on a rotary evaporator at 65°C. The brown oil residue was dried at 70° C. in vacuo (0.8 bar) for 1 hto give 222.8 g of crude material. The crude product weight was >100%.Due to the relative instability of the product on silica gel, the crudeproduct is usually used directly in the next step without purification).The diastereomeric ratio of the crude mixture was determined by protonNMR: (2S)/(2R): 86:14. The minor and major epoxide diastereomers werecharacterized in this mixture by tlc analysis (silica gel, 10% ethylacetate/hexane), Rf=0.29 & 0.32, respectively. An analytical sample ofeach of the diastereomers was obtained by purification on silica-gelchromatography (3% ethyl acetate/hexane) and characterized as follows:

N,N,αS-Tris(phenylmethyl)-2S-oxiranemethanamine

¹H NMR (400 MHz, CDCl₃) δ 2.49 and 2.51 (AB-System, 1H, J_(AB)=2.82),2.76 and 2.77 (AB-System, 1H, J_(AB)=4.03), 2.83 (m, 2H), 2.99 & 3.03(AB-System, 1H, J_(AB)=10.1 Hz), 3.15 (m, 1H), 3.73 & 3.84 (AB-System,4H, J_(AB)=14.00), 7.21 (m, 15H); ¹³C NMR (400 MHz, CDCl₃) δ 139.55,129.45, 128.42, 128.14, 128.09, 126.84, 125.97, 60.32, 54.23, 52.13,45.99, 33.76; HRMS calcd for C₂₄H₂₆NO (M+1) 344.477, found 344.2003.

N,N,αS-Tris(phenylmethyl)-2R-oxiranemethanamine

¹H NMR (300 MHz, CDCl₃) δ 2.20 (m, 1H), 2.59 (m, 1H), 2.75 (m, 2H), 2.97(m, 1H), 3.14 (m, 1H), 3.85 (AB-System, 4H), 7.25 (m, 15H).HPLC onchiral stationary phase: Pirkle-Whelk-O 1 column (250×4.6 mm I.D.),mobile phase: hexane/isopropanol (99.5:0.5, v/v), flow-rate: 1.5 ml/min,detection with UV detector at 210 nm. Retention time of (8):9.38 min.,retention time of enanatiomer of (4):13.75 min.

Alternatively, a solution of the crude aldehyde 0.074 mol andchloroiodomethane (7.0 ml, 0.096 mol) in tetrahydrofuran (285 ml) wascooled to −78° C., under a nitrogen atmosphere. A 1.6 M solution ofn-butyllithium in hexane (25 ml, 0.040 mol) was then added at a rate tomaintain the temperature at −75° C. (addition time—15 min.). After thefirst addition, additional chloroiodomethane (1.6 ml, 0.022 mol) wasadded again, followed by n-butyllithium (23 ml, 0.037 mol), keeping thetemperature at −75° C. The mixture was stirred for 15 min. Each of thereagents, chloroiodomethane (0.70 ml, 0.010 mol) and n-butyllithium (5ml, 0.008 mol) were added 4 more times over 45 min. at −75° C. Thecooling bath was then removed and the solution warmed to 22° C. over 1.5hr. The mixture was poured into 300 ml of saturated aq. ammoniumchloride solution. The tetrahydrofuran layer was separated. The aqueousphase was extracted with ethyl acetate (1×300 ml). The combined organiclayers were washed with brine, dried over magnesium sulfate, filteredand concentrated to give a brown oil (27.4 g). The product could be usedin the next step without purification. The desired diastereomer can bepurified by recrystallization at a subsequent step. The product couldalso be purified by chromatography.

Alternatively, a solution ofαS-[Bis(phenylmethyl)amino]benzene-propanaldehyde (178.84 g, 0.54 mol)and bromochloromethane (46 mL, 0.71 mol) in tetrahydrofuran (1.8 L) wascooled to −30 to −35° C. (colder temperature such as −70° C. also workedwell but warmer temperatures are more readily achieved in large scaleoperations) in a stainless steel reactor under a nitrogen atmosphere. Asolution of n-butyllithium in hexane (1.6 M, 340 mL, 0.54 mol) was thenadded at a rate that maintained the temperature −25° C. After additionthe mixture was stirred at −30 to −35° C. for 10 minutes. More additionsof reagents were carried out in the following manner: (1) additionalbromochloromethane (14 mL) was added, followed by n-butyllithium (102ml) at <−25° C. After addition the mixture was stirred at −30 to −35° C.for 10 minutes. This was repeated once. (2) Additionalbromochloromethane (7 mL, 0.11 mol) was added, followed byn-butyllithium (51 mL, 0.082 mol) at <−25° C. After addition the mixturewas stirred at −30 to −35° C. for 10 minutes. This was repeated 5 times.(3) Additional bromochloromethane (7 mL, 0.11 mol) was added, followedby n-butyllithium (51 mL, 0.082 mol) at <−25° C. After addition themixture was stirred at −30 to −35° C. for 10 minutes. This was repeatedonce. The external cooling was stopped and the mixture warmed to ambienttemp. over 4 to 16 hours when TLC (silica gel, 20% ethyl acetate/hexane)indicated that the reaction was completed. The reaction mixture wascooled to 10° C. and quenched with 1452 g of 16% ammonium chloridesolution (prepared by dissolving 232 g of ammonium chloride in 1220 mLof water), keeping the temperature below 23° C. The mixture was stirredfor 10 minutes and the organic and aqueous layers were separated. Theaqueous phase was extracted with ethyl acetate (2×500 mL). The ethylacetate layer was combined with the tetrahydrofuran layer. The combinedsolution was dried over magnesium sulfate (220 g), filtered andconcentrated on a rotary evaporator at 65° C. The brown oil residue wasdried at 70° C. in vacuo (0.8 bar) for 1 h to give 222.8 g of crudematerial.

Example 2

Preparation ofN-[[3S-(phenylmethylcarbamoyl)amino]-2R-hydroxy-4-phenyl]-1-[(2-methylpropyl)amino-2-(1,1-dimethylethoxyl)carbonyl]butane

To a solution of 7.51 g (20.3 mmol) ofN-[[3S-(phenylmethylcarbamoyl)amino]-2R-hydroxy-4-phenylbutyl]-N-(2-methylpropyl)aminein 67 mL of anhydrous tetrahydrofuran was added 2.25 g (22.3 mmol) oftriethylamine. After cooling to 0° C., 4.4 g (20.3 mmol) ofdi-tert-butyldicarbonate was added and stirring continued at roomtemperature for 21 hours. The volatiles were removed in vacuo, ethylacetate added, then washed with 5% citric acid, saturated sodiumbicarbonate, brine, dried over magnesium sulfate, filtered andconcentrated to afford 9.6 g of crude product. Chromatography on silicagel using 30% ethyl acetate/hexane afforded 8.2 g of pureN-[[3S-(phenylmethylcarbamoyl)amino]-2R-hydroxy-4-phenyl]-1-[(2-methylpropyl)amino-2-(1,1-dimethylethoxy)carbonyl]butane,mass spectum m/e=477 (M+Li).

Example 3A

Preparation of phenylmethyl [2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate

To a solution ofN(3(S)-benzyloxycarbonylamino-2(R)-hydroxy-4-phenylbutyl) N-isoamylamine(2.0 gm, 5.2 mmol) and triethylamine (723 uL, 5.5 mmol) indichloromethane (20 mL) was added dropwise methanesulfonyl chloride (400uL, 5.2 mmol). The reaction mixture was stirred for 2 hours at roomtemperature, then the dichloromethane solution was concentrated to ca. 5mL and applied to a silica gel column (100 gm). The column was elutedwith chloroform containing 1% ethanol and 1% methanol. The phenylmethyl[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate was obtained asa white solid Anal. Calcd for C₂₄H₃₄N₂O₅S: C, 62.31; H, 7.41; N, 6.06.Found: C, 62.17; H, 7.55; N, 5.97.

Example 3B

Preparation of phenylmethyl [2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate

From the reaction ofN[3(S)-benzyloxycarbonylamino-2(R)-hydroxy-4-phenylbutyl] N-isoamylamine(1.47 gm, 3.8 mmol), triethylamine (528 uL, 3.8 mmol) andbenzenesulfonyl chloride (483 uL, 3.8 mmol) one obtains phenylmethyl[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-carbamate. Columnchromotography on silica gel eluting with chloroform containing 1%ethanol afforded the pure product. Anal. Calcd for C₂₉H₃₆N₂O₅S: C,66.39; H, 6.92; N, 5.34. Found: C, 66.37; H, 6.93; N, 5.26.

Example 4

Preparation of Phenylmethyl [2R-hydroxy-3-[(3-methylbutyl)(n-propanesulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate

To a solution ofN[3(S)-benzyloxycarbonylamino-2(R)-hydroxy-4-phenylbutyl) N-isoamylamine(192 mg, 0.5 mmol) and triethylamine (139 uL, 1.0 mmol) indichloromethane (10 mL) was added dropwise trimethylsilyl chloride (63uL, 0.5 mmol). The reaction was allowed to stir for 1 hour at roomtemperature, cooled to 0° C. with an ice bath and then n-propanesulfonylchloride (56 uL, 0.5 mmol) was added dropwise. The reaction mixture wasstirred for 1.5 hours at room temperature, then diluted with ethylacetate (50 mL) and washed sequentially with 1N HCl, water, saturatedsodium bicarbonate solution, and saturated sodium chloride solution (25mL each). The organic solution was dried over magnesium sulfate,filtered and concentrated to an oil. The oil was stirred with methanol(10 mL) for 16 hours, concentrated and the residue chromatographed onsilica gel (50 gm) eluting with 10% ethyl acetate in hexane (450 mL),then with 1:1 ethyl acetate/hexane. The phenylmethyl(2R-hydroxy-3-[(3-methylbutyl)(n-propanesulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate wasrecrystallized from ethyl ether/hexane to afford a white solid Anal.Calcd. for C₂₆H₃₈N₂O₅: C, 63.64; H, 7.81; N, 5.71. Found: C, 63.09; H,7.74; N, 5.64.

Example 5

The procedure described in Example 2 was used to prepare phenylmethyl[2S-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate.

To a solution ofN[3(S)-benzyloxycarbonylamino-2(S)-hydroxy-4-phenylbutyl] N-isoamylamine(192 mg, 0.5 mmol) and triethylamine (139 uL, 0.55 mmol) indichloromethane (8 mL) was added dropwise methanesulfonyl chloride (39uL, 0.55 mmol). The reaction mixture was stirred for 16 hours at roomtemperature, then the dichloromethane solution was applied to a silicagel column (50 gm). The column eluted with dichloromethane containing2.5% methanol. The phenylmethyl [2S-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylmethyl)propyl)carbamate was obtained asa white solid Anal. Calcd. for C₂₄H₃₄N₂O₅S ⋄ 0.2 H₂O: C, 61.83; H, 7.44;N, 6.01. Found: C, 61.62; H, 7.40; N, 5.99.

Example 6

Following the procedures of the previous Examples 1-5, the intermediatecompounds set forth in Tables 1A and 1B were prepared.

Tables 1A and 1C also provide calculated versus found mass spectroscopyresults for the compounds disclosed herein.

TABLE 1A

Entry R³ R⁴  1 isoamyl p-fluorophenyl  2 isoamyl p-nitrophenyl  3isoamyl o-nitrophenyl  4 isoamyl β-naphthyl  5 isoamyl 2-thienyl  6isoamyl benzyl  7 isobutyl p-fluorophenyl  8 p-fluorobenzyl phenyl  94-pyridylmethyl phenyl 10 cyclohexylmethyl phenyl 11 allyl phenyl 12propyl phenyl 13 cyclopropylmethyl phenyl 14 methyl phenyl 15 propargylphenyl 16 isoamyl p-chlorophenyl 17 isoamyl p-methoxyphenyl 18 isoamylm-nitrophenyl 19 isoamyl m-trifluoromethylphenyl 20 isoamylo-methoxycarbonylphenyl 21 isoamyl p-acetamidophenyl 22 isobutyl phenyl23 —CH₂Ph —Ph 24

—Ph 25

—Ph 26

—Ph 27

—Ph 28

—Ph 29 —CH₂CH═CH₂ —Ph 30

—Ph 31

—Ph 32 —CH₂CH₂Ph —Ph 33 —CH₂CH₂CH₂CH₂OH —Ph 34 —CH₂CH₂N(CH₃)₂ —Ph 35

—Ph 36 —CH₃ —Ph 37 —CH₂CH₂CH₂SCH₃ —Ph 38 —CH₂CH₂CH₂S(O)₂CH₃ —Ph 39—CH₂CH₂CH(CH₃)₂

40 —CH₂CH₂CH(CH₃)₂ —CH₂CH₂CH₃ 41 —CH₂CH₂CH(CH₃)₂ —CH₃ 42 —CH₂CH₂CH(CH₃)₂

43 —CH₂CH₂CH(CH₃)₂

44 —CH₂CH₂CH(CH₃)₂

45 —CH₂CH(CH₃)₂

46 —CH₂CH(CH₃)₂

47 —CH₂CH(CH₃)₂

48 —CH₂CH₂CH₃

49 —CH₂CH₂CH₂CH₃

50 —CH₂CH₂CH(CH₃)₂ —CF₃ 51 —CH₂CH(CH₃)₂ —CH₃ 52 —CH₂CH₂CH(CH₃)₂ —CH₂Cl53 —CH₂CH(CH₃)₂

54 —CH₂CH(CH₃)₂

55 —CH₂CH(CH₃)₂ —CH═CH₂ 56 —CH₂—CH)CH₃)(CH₂CH₃)

MASS MEASUREMENT R³ R⁴ MOL FORM CALC FOUND

C₂₉H₃₆N₂O₅S 531 (M + Li) 531

C₂₉H₃₆N₂O₆S 541 (M + H) 541

C₃₀H₃₆N₂O₆S 555.2529 (M + H) 555.2582

C₂₈H₃₃N₂O₅SF 529.2172 (M + H) 521.2976

C₂₉H₃₆N₂O₅S₂ 563 (M + Li) 563

C₂₉H₃₆N₂O₆S₂ 573 (M + H) 573

C₂₉H₃₆N₂O₇S₂ 595 (M + Li) 595

TABLE 1B

Entry R R³ 1

—CH₂Ph 2

—CH₂CH₂CH(CH₃)₂ 3

—CH₂CH(CH₃)₂ 4

—CH₂CH(CH₃)₂ 5

—CH₂CH(CH₃)₂ 6

—CH₂CH(CH₃)₂ 7

—CH₂CH(CH₃)₂ 8

—CH₂CH(CH₃)₂ 9

—CH₂CH₂(CH₃)₂

TABLE 1C

Mass Determination X R⁸ FORMULA Calc Found H

C₂₇H₃₃N₃O₅S 512.2219 (M + H) 521.2267 OCH₃

C₂₈H₃₅N₃O₆S 548.2407 (M + Li) 548.2434 F

C₂₇H₃₂N₃O₅SF 530 (M + H) 530 Cl

C₂₇H₃₂N₃O₅SCl 546 (M +H) 546 NO₂

C₂₇H₃₂N₄O₇S 557 (M + H) 557 OH

C₂₇H₃₃N₃O₆S 528 (M + H) 528 OCH₃

C₂₈H₃₅N₃O₆S 542.2325 (M + H) 542.2362 OCH₃

C₂₈H₃₅N₃O₆S 548.2407 (M + Li) 548.2393 OCH₃

C₂₈H₃₅N₄O₆S 543 (M + H) 543 OCH₃

C₂₉H₃₆O₆N₂S 547.2454 (M + Li) 547.2475 OCH₃ tert-Butyl C₂₆H₃₈N₂O₆S513.2611 (M +Li) 513.2593 OCH₃

C₂₈H₃₅N₃O₇S 564 (M + Li) 564 OCH₃

C₂₈H₃₅N₃O₇S 564 (M + Li) 564

The following Examples 7-9 illustrate preparation of β-amino acidintermediates. These intermediates can be coupled to the intermediatecompounds of Examples 1-6 to produce inhibitor compounds of the presentinvention containing β-amino acids.

Example 7

A. Preparation of 4(4-methoxybenzyl)itaconate

A 5 L three-necked round bottomed flask equipped with constant pressureaddition funnel, reflux condenser, nitrogen inlet, and mechanicalstirred was charged with itaconic anhydride (660.8 g, 5.88 mol) andtoluene (2300 mL). The solution was warmed to reflux and treated with4-methoxybenzyl alcohol (812.4 g, 5.88 mol) dropwise over a 2.6 hperiod. The solution was maintained at reflux for an additional 1.5 hand then the contents were poured into three 2 L erlenmeyer flasks tocrystallize. The solution was allowed to cool to room temperaturewhereupon the desired mono-ester crystallized. The product was isolatedby filtration on a Buchner funnel and air dried to give 850.2 g, 58% ofmaterial with mp 83-85° C., a second crop, 17% was isolated aftercooling of the filtrate in an ice bath. ¹H NMR (CDCl₃) 300 MHz 7.32(d,8.7 Hz, 2H), 6.91(d, J=8.7 Hz, 2H), 6.49 (s,1H), 5.85 (s, 1H), 5.12(s,2H), 6.91(J=8.7 Hz, 2H, 6.49 (s, 1H), 5.85 (s,1H), 5.``1 (s,2H), 3.83(s, 3H), 3.40 (s, 2H).

B. Preparation of Methyl 4(4-methoxybenzyl) itaconate

A 5 L three-necked round bottomed flask equipped with reflux condenser,nitrogen inlet, constant pressure addition funnel and mechanical stirrerwas charged with 4(4-methoxybenzyl) itaconate (453.4 g, 1.81 mol) andtreated with 1,5-diazabicyclo [4.3.0]non-5-ene (275.6 g, 1.81 mol),(DBN), dropwise so that the temperature did not rise above 15° C. Tothis stirring mixture was added a solution of methyl iodide (256.9 g,1.81 mol) in 250 mL of toluene from the dropping funnel over a 45 mperiod. The solution was allowed to warm to room temperature and stirredfor an additional 3.25 h.

The precipitated DBN hydroiodide was removed by filtration, washed withtoluene and the filtrate poured into a separatory funnel. The solutionwas washed with sat. aq. NaHCO₃ (2×500 mL), 0.2 N HCl (2×500 mL), andbrine (2×500 mL), dried over anhyd. MgSO₄, filtered and the solventremoved in vacuo. This gave a clear colorless oil, 450.2 g, 94% whoseNMR was consistent with the assigned structure. ¹H NMR (CDCl₃) 300 MHz7.30 (d, J=8.7 Hz, 2 H), 6.90 (d, J=8.7 Hz, 2 H), 6.34 (s, 1 H), 5.71(s, 1 H), 5.09 (s, 2 H), 3.82 (s, 3 H), 3.73 (s, 3 H), 3.38 (s, 2 H).¹³C NMR (CDCl₃) 170.46, 166.47, 159,51, 133.55, 129.97, 128.45, 127.72,113.77, 66.36, 55.12, 51.94, 37.64.

C. Preparation of Methyl 4(4-methoxybenzyl) 2(R) -methylsuccinate

A 500 mL Fisher-Porter bottle was charged with methyl 4(4-methoxybenzyl)itaconate (71.1 g, 0.269 mol), rhodium (R,R) DiPAMP catalyst (204 mg,0.269 mmol, 0.1 mol %) and degassed methanol (215 mL). The bottle wasflushed 5 times with nitrogen and 5 times with hydrogen to a finalpressure of 40 psig. The hydrogenation commenced immediately and afterca. 1 h the uptake began to taper off, after 3 h the hydrogen uptakeceased and the bottle was flushed with nitrogen, opened and the contentsconcentrated on a rotary evaporator to give a brown oil that was takenup in boiling iso-octane (ca. 200 mL, this was repeated twice), filteredthrough a pad of celite and the filtrate concentrated in vacuo to give66.6 g, 93% of a clear colorless oil, ¹H NMR (CDCl³ 300 MHz 7.30 (d,J=8.7 Hz, 2 H), 6.91 (d, J=8.7 Hz, 2 H), 5.08 (s, 2 H), 3.82 (s, 3 H),3.67 (s, 3 H), 3.95 (ddg, J=5.7, 7.5, 8.7 Hz, 1 H), 2.79 (dd, J=8.1,16.5 Hz, 1 H), 2.45 (dd, J=5.7, 16.5 Hz, 1 H), 1.23 (d, J=7.5 Hz, 3 H).

D. Preparation of Methyl 2(R)-methylsuccinate

A 3 L three-necked round-bottomed flask equipped with a nitrogen inlet,mechanical stirrer, reflux condenser and constant pressure additionfunnel was charged with methyl 4(4-methoxybenzyl) 2 (R)-methylsuccinate(432.6 g, 1.65 mol) and toluene (1200 mL). The stirrer was started andthe solution treated with trifluoroacetic acid (600 mL) from thedropping funnel over 0.25 h. The solution turned a deep purple color andthe internal temperature rose to 45° C. After stirring for 2.25 h thetemperature was 27° C. and the solution had acquired a pink color. Thesolution was concentrated on a rotary evaporator. The residue wasdiluted with water (2200 mL) and sat. aq. NaHCO₃ (1000 mL). AdditionalNaHCO₃ was added until the acid had been neutralized. The aqueous phasewas extracted with ethyl acetate (2×1000 mL) to remove the by-productsand the aqueous layer was acidified to pH=1.8 with conc. HCl. Thissolution was extracted with ethyl acetate (4×1000 mL), washed withbrine, dried over anhyd. MgSO₄, filtered and concentrated on a rotaryevaporator to give a colorless liquid 251 g, >100% that was vacuumdistilled through a short path apparatus cut 1: bath temperature 120° C.@>1 mm, bp 25-29° C.; cut 2: bath temperature 140° C. @0.5 mm, bp95-108° C., 151 g, [α]_(d) @25° C.=+1.38° C. (c=15.475, MeOH),[α]_(d)=+8.48° C. (neat); cut 3: bath temperature 140° C., bp 108° C.,36 g, [α]_(d)@25° C.=+1.49° C. (c=15.00, MeOH), [α]_(d)=+8.98° C.(neat). Cuts 2 and 3 were combined to give 189 g, 78% of product, ¹H NMR(CDCl₃) 300 MHz 11.6 (brs, 1 H), 3.72 (s, 3 H), 2.92 (ddq, J=5.7, 6.9,8.0 Hz, 1 H), 2.81 (dd, J=8.0, 16.8 Hz, 1 H), 2.47 (dd, J=5.7, 16.8 Hz,1 H), 1.26 (d, J=6.9 Hz, 3 H).

E. Preparation of Methyl Itaconate

A 50 mL round bottomed flask equipped with reflux condenser, nitrogeninlet and magnetic stir bar was charged with methyl 4(4-methoxybenzyl)itaconate (4.00 g, 16 mmol), 12 mL of touluene and 6 mL oftrifluoroacetic acid. The solution was kept at room temperature for 18hours and then the volatiles were removed in vacuo. The residue wastaken up in ethyl acetate and extracted three times with saturatedaqueous sodium bicarbonate solution. The combined aqueous extract wasacidified to pH=1 with aqueous potassium bisulfate and then extractedthree times with ethyl acetate. The combined ethyl acetate solution waswashed with saturated aqueous sodium chloride, dried over anhydrousmagnesium sulfate, filtered, and concentrated in vacuo. The residue wasthen vacuum distilled to give 1.23 g, 75% of pure product, bp 85-87@0.1mm. ¹H NMR (CDCl₃) 300 MHz 6.34 (s, 1 H), 5.73 (s, 2 H), 3.76 (s, 3 H),3.38 (s, 2 H). ¹³C NMR (CDCl₃) 177.03, 166.65, 129.220, 132.99, 52.27,37.46.

F. Curtius Rearrangement of Methyl 2(R)-methylsuccinate: Preparation ofMethyl N-Moz-α-methyl β-alanine.

A 5 L four necked round bottomed flask equipped with a nitrogen inlet,reflux condenser, mechanical stirrer, constant pressure addition funnel,and thermometer adapter was charged with methyl 2(R)-methylsuccinate(184.1 g, 1.26 mol), triethylamine (165.6 g, 218 mL, 1.64 mol, 1.3equivalents), and toluene (1063 mL). The solution was warmed to 85° C.and then treated dropwise with a solution of diphenylphosphoryl azide(346.8 g, 1.26 mol) over a period of 1.2 h. The solution was maintainedat that temperature for an additional 1.0 h and then the mixture wastreated with 4-methoxybenzyl alcohol (174.1 g, 1.26 mol) over a 0.33 hperiod from the dropping funnel. The solution was stirred at 88° C. foran additional 2.25 h and then cooled to room temperature. The contentsof the flask were poured into a separatory funnel and washed with sat.aq. NaHCO₃ (2×500 mL), 0.2 N HCl (2×500 mL), brine (1×500 mL), driedover anhyd. MgSO₄, filtered, and concentrated in vacuo to give 302.3 g,85% of the desired product as a slightly brown oil. ¹H NMR (CDCl₃) 300MHz 7.32 (d, J=8.4 Hz, 2 H), 6.91 (d, J=8.4 Hz, 2 H), 5.2 (brm, 1 H),5.05 (s, 2 H), 3.83 (s, 3 H), 3.70 (s, 3 H), 3.35 (m, 2 H), 2.70 (m, 2H), 1.20 (d, J=7.2 Hz, 3 H).

G. Hydrolysis of Methyl N-Moz-α-methyl β-alanine:

Preparation of α-methyl β-alanine Hydrochloride

A 5 L three-necked round bottomed flask equipped with a refluxcondenser, nitrogen inlet and mechanical stirrer was charged with methylN-Moz-α-methyl β-alanine (218.6 g, 0.78 mol), glacial acetic acid (975mL) and 12 N hydrochloric acid (1960 mL). The solution was then heatedto reflux for 3 h. After the solution had cooled to room temperature(ca. 1 h) the aqueous phase was decanted from organic residue (polymer)and the aqueous phase concentrated on a rotary evaporator. Upon additionof acetone to the concentrated residue a slightly yellow solid formedthat was slurried with acetone and the white solid was isolated byfiltration on a Buchner funnel. The last traces of acetone were removedby evacuation to give 97.7 g, 90% of pure product, mp 128.5-130.5° C.[α]_(d)@25° C.=9.0° C. (c=2.535, Methanol). ¹H NMR (D₂O) 300 MHz 3.29(dd, J=8.6, 13.0 Hz, 1 H), 3.16 (dd, J=5.0, 13.0 m Hz, 1 H), 2.94 (ddq,J=7.2, 5.0, 8.6 Hz, 1 H), 1.30 (d, J=7.2 Hz, 3 H); ¹³C NMR (D₂O) 180.84,44,56, 40.27, 17.49.

H. Preparation of N-Boc α-Methyl β-Alanine

A solution of a-methyl b-alanine hydrochloride (97.7 g, 0.70 mol) inwater (1050 mL) and dioxane (1050 mL) the pH was adjusted to 8.9 with2.9 N NaOH solution. This stirring solution was then treated withdi-tert-butyl pyrocarbonate (183.3 g, 0.84 mol, 1.2 equivalents) all atonce. The pH of the solution was maintained between 8.7 and 9.0 by theperiodic addition of 2.5 N NaOH solution. After 2.5 h the pH hadstabilized and the reaction was judged to be complete. The solution wasconcentrated on a rotary evaporator (the temperature was maintained at<40° C.) The excess di-tert-butyl pyrocarbonate was removed byextraction with dichloromethane and then the aqueous solution wasacidified with cold 1 N HCl and immediately extracted with ethyl acetate(4×1000 mL). The combined ethyl acetate extract was washed with brine,dried over anhyd, MgSO₄, filtered and concentrated on a rotaryevaporator to give a thick oil 127.3 g, 90% crude yield that was stirredwith n-hexane whereupon crystals of pure product formed, 95.65 g, 67%,mp 76-78° C. [α]_(d)@25° C.=−11.8° C. (c=2.4, EtOH). A second crop wasobtained by concentration of the filtrate and dilution with hexane, 15.4g, for a combined yield of 111.05 g, 78%. ¹H NMR:acetone D₆) 300 MHz11.7 (brs. 1 H), 6.05 (brs 1 H), 3.35 (m, 1 H), 3.22 (m, 1 H), 2.50 (m,1 H), 1.45 (s, 9 H), 1.19 (d, J=7.3 Hz, 3 H); ¹³C NMR (acetone D₆)177.01, 79,28, 44.44, 40.92, 29.08, 15.50. Elemental analysis calc'd.for C₉H₁₇NO₄: C, 53.19, H, 8.42; N, 6,89. Found: C, 53,36; H, 8.46; N,6.99.

I. Preparation of N-4-Methoxybenzyloxycarbonyl α-Methyl β-Alanine

A solution of N-4-methoxybenzyloxycarbonyl α-methyl β-alanine methylester (2.81 g, 10.0 mmol) in 30 mL of 25% aqueous methanol was treatedwith lithium hydroxide (1.3 equivalents) at room temperature for aperiod of 2 h. The solution was concentrated in vacuo and the residuetaken up in a mixture of water and ether and the phases separated andthe organic phase discarded. The aqueous phase was acidified withaqueous potassium hydrogen sulfate to pH=1.5 and then extracted threetimes with ether. The combined ethereal phase was washed with saturatedaqueous sodium chloride solution, dried over anhydrous magnesiumsulfate, filtered and concentrated in vacuo to give 2.60 g, 97% ofN-4-Methoxybenzyloxycarbonyl α-methyl β-alanine (N-Moz-AMBA) which waspurified by recrystallization from a mixture of ethyl acetate and hexaneto give 2.44 g, 91% of pure product, mp 96-97° C., MH+=268. ¹H NMR(D₆-acetone/300 MHz) 1.16 (3 H, d, J=7.2 Hz), 2.70 (1 H, m), 3.31 (2 H,m), 3.31 (3 H, s), 4.99 (2 H, s), 6.92 (2 H, 4, J=8.7 Hz), 7.13 (2 H, d,J=8.7 Hz).

Example 8

Following generally the procedure of Example 7, the β-amino acids setforth in Table 2 were prepared.

TABLE 2

Entry R¹ R¹′ R¹″ 1 —CH₃ H H 2 —CH(CH₃)₂ H H 3 —C(CH₃)₃ H H 4 H H H 5 H—CH₃ H 6 H —CH₃ —CH₃ 7 H H —CO₂CH₃ 8 H H —CONH₂ 9 —CH₂CH₃ H H 10—CH₂CH(CH₃)₂ H H 11 —CH₂C₆H₅ H H 12

H H 13

H H 14 —CH₂COOH H H 15 H —CH(CH₃)₂ H 16 H —CH₂CH(CH₃)₂ H 17 H

H 18 H

H 19 H

H 20 H

H 21 H —(CH₂)₃CH(C₆H₅)₂ H

Example 9

Utilizing generally the procedure set forth in Example 7, the followingβ-amino acid compounds were prepared.

Example 10A

Preparation of 4-Pyridinecarboxamide,N-[2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]

To a solution of 231 mg (0.57 mmol) of 2R-hydroxy-3-[(2-methylpropyl)(2-methylpropyl) (4-methoxyphenyl)sulfonyl]amino-1S-(phenylmethyl)propylamine in 3 mL of methylene chloride at 0°C., was added 288 mg (2.85 mmol) of triethylamine and then 112 mg (0.63mmol) of isonicotinoyl chloride hydrochloride. After 19 hours at roomtemperature, the solvent was removed, ethyl acetate added, then washedwith saturated sodium bicarbonate, brine, dried with magnesuim sulfate,filtered and concentrated to afford 290 mg of crude product. This waschromatographed on silica get using 3-5% isopropanol/methylene chlorideas eluent to afford 190 mg of the desired compound; mass spectrum calc.for C₂₇H₃₄N₃O₅S (M+H) 512.2219; found 512.2280.

Example 10B

Prepration of Benzamide,N-[2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-2,6-dimethyl

To a solution of 83 mg (0.55 mmol) of 2,6-dimethylbenzoic acid and 125mg (0.82 mmol) of N-hydroxybenzotriazole in 3 mL of anhydrous DMF at 0°C. was added 117 mg (0.61 mmol) of1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. After 2hours at 0° C., 203 mg (0.50 mmol) of 2R-hydroxy-3-[(2-methylpropyl)(4-methoxyphenyl)sulfonyl]amino-1S-(phenylmethyl)propylamine was added.After 22 hours at room temperature, the solvent was removed in vacuo,ethyl acetate added, then washed with saturated sodium bicarbonate,brine, dried over magnesium sulfate, filtered and concentrated to afford300 mg of crude product. Chromatography on silica gel using 20-50% ethylacetate/hexane afforded 37 mg of the desired product; mass spectrumcalcd for C₃₀H₃₈N₂O₅S (M+H) 539.2580; found 539.2632.

Example 11A

Preparation of N1-[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylmethyl)propyl]-2S-[(2-quinolinylcarbonyl)amino]butanediamide

Part A:

A solution of phenylmethyl [2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1-S-(phenylmethyl)-propyl]carbamate prepared asin Example 3 (100 mg) in methanol (10 mL) was hydrogenated over 10%palladium on carbon for 2 hours, filtered through diatomaceous earth andconcentrated to give the product as an oil.

Part B:

A solution of N-CBZ-L-asparagine (61 mg, 0.23 mmol) andN-hydroxybenzotriazole (33 mg, 0.22 mmol) in DMF (2 mL) was cooled to 0°C. with an ice bath and then EDC (42 mg, 0.22 mmol) was added. Thesolution was stirred for 30 minutes at 0° C. and then the product ofPart A (69 mg, 0.21 mmol) in DMF (2 mL) was added. After 30 minutes at0° C. the reaction was allowed to warm to room temperature and stir for16 hours. The reaction mixture was then poured into a 50% saturatedaqueous solution of sodium bicarbonate (100 mL) and the resulting whiteprecipitate collected by suction filtration, washed with water and driedin vacuo. The phenylmethyl [3-amino-1S-[[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylemthyl)amino]carbonyl]-3-oxopropyl]carbamatewas obtained as a white solid Anal. Calcd. for C₂₈H₄₀N₄O₇S. 0.5 H₂O: C,57.42; H, 7.06; N, 9.57. Found: C, 57.72; H, 7.21; N, 9.24.

Part C:

A solution of phenylmethyl [3-amino-1S-[[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1-S-(phenylmethyl)amino]carbonyl]-3-oxopropyl]carbamate(135 mg, 0.23) in methanol (15 mL) was hydrogenated over 10% palladiumon carbon for 6 hours, filtered through diatomaceous earth andconcentrated to give the product as an oil.

Part D:

To a solution of the product from Part C (101 mg, 0.23 mmol) in DMF (5mL) was added 2-quinoline carboxylic acid N-hydroxysuccinimide ester (67mg, 0.25 mmol). The reaction was stirred at room temperature for 16hours, then poured into a 50% saturated solution of sodium bicarbonate(60 mL). The resulting solid was collected by suction filtration washedwith water and dried in vacuo. The N1-[2R-hydroxy-3-[(3-methybutyl)(methylsulfonyl)-amino]-1S-(phenylmethyl)propyl]-2-S-[(2-quinolinylcarbonyl)-amino]butanediamidewas obtained as a white solid Anal. Calcd. for C₃₀H₃₉N₅O₆S. 0.1 H₂O: C,58.52; H, 6.71; N, 11.37. Found: C, 58.34; H, 6.35; N, 11.13.

Example 11B

Preparation of N1-[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-2S-[(2-quinolinylcarbonyl)amino]butanediamide.

Part A:

The CBZ protected compound phenylmethyl [2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]carbamate (200 mg, 0.38mmol) was deprotected by hydrogenation over 10% palladium on carbon andthe resulting product obtained as an oil.

Part B:

The free amine from Part A was coupled with N-CBZ-L-asparagine (109 mg,0.41 mmol) in the presence of N-hydroxybenzotriazole (63 mg, 0.41 mmol)and EDC (77 mg, 0.40 mmol) to give phenylmethyl[3-amino-1S-[[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)amino]carbonyl]-3-oxopropyl]carbamateas a white solid Anal. Calcd. for C₃₃H₄₂N₄O₇S: C, 62.05; H, 6.63; N,8.77. Found: C, 61.86; H, 6.60; N, 8.64.

Part C:

The product of Part B (110 mg, 0.17) was deprotected by hydrogenationover 10% palladium on carbon to give the product as an oil.

Part D:

The resulting free amine was coupled with 2-quinoline carboxylic acidN-hydroxysuccinimide ester (45 mg, 0.17 mmol) to giveN1-[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-2S-[(2-quinolinylcarbonyl)amino]butanediamideas a white solid Anal. Calcd. for C₃₅H₄₁N₅O₆S: C, 63.71; H, 6.26; N,10.61. Found: C, 63.59; H, 6.42; N, 10.42.

Example 12A

Preparation of2S-[[(dimethylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1-S-(phenylmethyl)propyl]-3,3-dimethylbutanamide

Part A:

To a solution of N-CBZ-L-tert-leucine (100 mg, 0.38 mmol) andN-hydroxybenzotriazole (52 mg, 0.34 mmol) in DMF (3 mL) was added EDC(65 mg, 0.34 mmol). The solution was stirred for 60 minutes at roomtemperature and then the product of Example 10, Part A (105 mg, 0.32mmol) in DMF (2 mL) was added. The reaction was stirred for 16 hours atroom temperature, then poured into a 50% saturated solution of sodiumbicarbonate (50 mL). The aqueous mixture was extrated twice with ethylacetate (25 mL). The combined ethyl acetate layers were washed withwater (25 mL) and dried over magnesium sulfate. Filtration andconcentration produced an oil which was chromatographed on silica gel(50 gm) eluting with 2.5% methanol in dichloromethane. The phenylmethyl[1S-[[[2R-hydroxy-3-[(3-methylbutyl)-(methylsulfonyl)amino]-1S-(phenylmethyl)propyl]amino]-carbonyl]-2,2-dimethylpropyl]carbamatewas obtained as a gummy solid Anal. Calcd. for C₃₀H₄₅N₃O₆S ⋄ 2.2 H₂O: C,58.55; H, 8.09; N, 6.83. Found: C, 58.38; H, 7.77; N, 7.10.

Part B:

A solution of phenylmethyl [1S-[[[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonylamino]-1-S-(phenylmethyl)propyl]amino]carbonyl]-2,2-dimethylpropyl]carbamate(100 mg, 0.17 mmol) in methanol (10 mL) was hydrogenated over 10%palladium on carbon for 2 hours. The reaction was filtered throughdiatomaceous earth and concentrated to an oil.

Part C:

N,N-dimethylglycine (20 mg, 0.19 mmol), N-hydroxybenzotriazole (28 mg,0.18 mmol) and EDC (35 mg, 0.18 mmol) were stirred in DMF (4 mL) at roomtemperature for 40 minutes. The product from Part B in DMF (4 mL) wasadded and the reaction mixture stirred for 16 hours, then poured into a50% saturated sodium bicarbonate solution (50 mL). The aqueous mixturewas extracted three times with dichloromethane (30 mL) which in turnwere washed with water (30 mL) and dried over magnesium sulfate.Filtration and concentration afforded an oil. The oil waschromatographed on silica gel (50 gm) eluting initially with 2.5%methanol in dichloromethane (400 mL) and then with 5% methanol indichloromethane. The2S-[[(dimethylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)(methylsulfonyl)amino]-1S-(phenylmethyl)-propyl]-3,3-dimethylbutanamidewas obtained as a white solid Anal. Calcd. for C₂₆H₄₆N₄O₅S ⋄0.5 CH₂Cl₂:C, 56.04; H, 8.34; N, 9.87. Found: C, 56.06; H, 8.36; N, 9.70.

Example 12B

Preparation of2S-[[(dimethylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methyl-butyl)(phenylsulfonyl)amino]-1S- (phenylmethyl)propyl]-3,3-dimethylbutaneamide

Part A:

To a solution of N-CBZ-L-tert-leucine (450 mg, 1.7 mmol) andN-hydroxybenzotriazole (260 mg, 1.7 mmol) in DMF (10 mL) was added EDC(307 mg, 1.6 mmol). The solution was stirred for 60 minutes at roomtemperature and then the product of Example 11, Part A (585 mg, 1.5mmol) in DMF (2 mL) was added. The reaction was stirred for 16 hours atroom temperature, then poured into a 50% saturated solution of sodiumbicarbonate (200 mL). The aqueous mixture was extracted thrice withethyl acetate (50 mL). The combined ethyl acetate layers were washedwith water (50 mL) and saturated NaCl solution (50 mL), then dried overmagnesium sulfate. Filtration and concentration produced an oil whichwas chromatographed on silica gel (50 gm) eluting with 20% ethyl acetatein hexane. The phenylmethyl [1S-[[[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]amino]carbonyl]-2,2-dimethylpropyl]carbamatewas obtained as a solid Anal. Calcd for C₃₅H₄₇N₃O₆S: C, 65.91; H, 7.43;N, 6.59. Found: C, 65.42; H, 7.24; N, 6.55.

Part B:

A solution of phenylmethyl [1S-[[[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)-amino]-1S-(phenylmethyl)propyl]amino]carbonyl]-2,2-dimethylpropyl]carbamate(200 mg, 0.31 mmol) in methanol (15 mL) was hydrogenated over 10%palladium on carbon for 2 hours. The reaction was filtered throughdiatomaceous earth and concentrated to an oil.

Part C:

The resulting free amine from part B (150 mg, 0.3 mmol) was combinedwithk diisopropylethylamine (114 uL, 0.33 mmol) in dichloromethan (5mL). To this was added bromoacetyl chloride (27 uL, 0.33 mmol) dropwise.The reaction was stirred for 30 minutes at room temperature, thendiluted with dichloromethane (30 mL) and extracted with 1 N HCl, water,and then saturated NaCl solution (25 mL each). The organic solution wasdried over MgSO₄ and concentrated to a solid. The2S-[[bromoacetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3,3-dimethylbutaneamidewas sufficiently pure for use in the next step. This material can alsobe prepared by substituting bromacetic anhydride for bromoacetylchloride, or one can use chloroacetyl chloride or chloracetic anyhdride.

Part D:

The product from part C was dissolved in dichloromethane (5 mL) anddiisopropylethylamine (114 uL, 0.66 mmol) and dimethylaminehydrochloride (53 mg, 0.66 mmol) were added. The reaction was stirredfor 18 hours then concentrated under a stream of nitrogen to about 1 mL.The residue was chromatographed on silica gel (50 gm) using 2% methanolin dichloromethane. The2S-[[(dimethylamino)-acetyl]amino]-N-[2R-hydroxy-3-[(3methylbutyl)-(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3,3-dimethylbutaneamidewas obtained as a solid. Anal. Calcd for C₃₁H₄₈N₄O₅S: C, 63.24; H, 8,22;N, 9.52. Found: C, 63.03; H, 8.01; N, 9.40.

Example 12C

Preparation of2S-[[(methylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methyl-butyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3,3-dimethylbutaneamide

2S-[[bromacetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)(phenysulfonyl)amino]-1S-(phenylmethyl)propyl]-3,3-dimethylbutaneamide(103 mg, 0.16 mmol) and 40% aqueous methylamine (42 uL, 0.49 mmol) werecombined in ethanol (2 mL) and stirred at room temperature for 24 hours.The reaction mixture was concentrated to dryness and triturated withether. The solid material was removed by filtration and the filtrateconcentrated to an oil. The oil was chromatographed on silica (50 gm)using 4% methanol in dichloromethane. The2S-[[(methylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3,3-dimethylbutaneamidewas obtained as a solid. Anal. Calcd for C₃₀H₄₆N₄O₅S: C, 62.69; H, 8.07;N, 9.75. Found: C, 62.38; H, 8.14; N, 9.60.

Example 12D

Preparation of Pentanamide,2S-[[(Dimethylamino))acetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)phenysulfonyl)amino]-1S-(phenylmethyl)propyl]3S-methyl-

Part A:

To a solution the amine product of Example 11, Part A; (2.79 g, 7.1mmol) in 27 mL of dioxane was added (2.3 g, 7.1 mmol) ofN-t-butylcarbonyl-L-isoleucine-N-hydroxysuccinamide ester, and thereaction was stirred under nitrogen atmospher for 16 hours. The contentsof the reaction were concentrated in vacuo, and the residue dissolved inethyl acetate, washed with potassium hydrogen sulfate (5% aqueous),saturated sodium bicarbonate, and saturated sodium chloride. The organiclayer was dried over magnesium sulfate, filtered and concentrated toyield 4.3 grams of crude material which was chromatographed using 3:1ethyl acetate: hexane to obtain 3.05 g, 72% yield of Pentanamide,2S-[[(1,1-dimethylethoxy)carbonyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3-methyl.

Part B

(3.05 g, 5.0 mmol) of the product from Part A; was dissolved in 20 mL of4 N HCl in dioxane and stirred under nitrogen atmosphere for 1.5 hours.The contents were concentrated in vacuo, and chased with diethyl ether.The crude hydrochloride salt was pumped on at 1 mm Hg until dry to yield2.54 g of product as its hydrochloride salt.

Part C:

(2.54 g, 5.0 mmol) of amine hydrochloride was dissolved in 50 mL oftetrahydrofuran and to this was added (1.01 g, 10 mmol) of4-methyl-morpholine, at which time a precipitate forms. To thissuspension was added chloroacetic anhydride (0.865 g, 5.0 mmol) andstirred for 40 minutes. The contents were concentrated in vacuo, and theresidue partitioned in ethyl acetate (200 mL) and 5% KHSO₄. The organiclayer was washed with saturated sodium bicarbonate, and saturated sodiumchloride, dried over magnesium sulfate, filtered and concentrated toyield the crude product. Purification by silica gel chromatography usingan eluant of 1:1 ethyl acetate; hexane yielded 1.89 grams of purechloroacetamide.

Part D:

To a solution of chloroacetamide (1.89 g, 3.2 mmol) from Part C, in 25mL of tetrahydrofuran was added 4.0 mL of 50% aqueous dimethylamine andthe solution was stirred for 1 hour. The solution was concentrated invacuo and the residue was dissolved in ethyl acetate and washed withwater. The organic layer was dried over magnesium sulfate, filtered andconcentrated to yield the crude product which was purified bycrystallization from ethyl acetate and isooctane to yield 1.80 g, (88%yield), mp.=121-122° C., HRes. MS. calc. 589.3424, found 589.3405.

Example 12E

Preparation of Pentanamide,2S-[[(Methylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3S-methyl-

To a solution of the chloroacetamide of Example 12D, Part C, (2.36 g,4.0 mmol) in tetrahydrofuran (25 mL) was added 3 mL of aqueousmethylamine 40 wt %, and the reaction stirred for 1 hour. The contentswere concentrated and the residue was partitioned between ethyl acetate(100 mL) and water (100 mL). The organic layer was dried over magnesiumsulfate, filtered and concentrated to yield the crude product, which waspurified by recrystallization from ethyl acetate heptane; (M+H) 575,HRes.found 575.3267.

Example 12F

Preparation of Pentanamide,2S-[[(Dimethylamino)acetyl]amino]-N-[2R-hydroxy-3-[(3-methypropyl)(4-methoxyphenylsulfonyl)amino]-1S-(phenylmethyl) propyl]-3S-methyl-

Part A:

To a solution of 2R-hydroxy-3-[(2-methylpropyl)(4-methoxyphenylsulfonyl)amino]1-S-propylamine (1.70 g, 4.18 mmol) in 40mL of dichloromethane was addedN-carbobenzyloxy-L-isoleucine-N-hydroxysuccinamide ester (1.51 g, 4.18mmol) and the solution stirred under nitrogen atmosphere for 16 hours.The contents were concentrated in vacuo and the residue was redissolvedin ethyl acetate. The ethyl acetate solution was washed with an aqueoussolution of 5% KHSO₄, saturated sodium bicarbonate, and saturated sodiumchloride, dried over magnesium sulfate, filtered, and concentrated toyield 2.47 g of crude product. The product was purified by silica gelchromatography using 1 2:1 hexane:ethyl acetate eluant to yield 2.3 g.(84% yield) of Pentanamide,2-[(carbobenzyloxy)amino]-N-[2-hydroxy-3-[(3-methylpropyl)(4-methoxyphenysulfonyl)amino]-1-(phenylmethyl)propyl]-3-methyl-,[4-(R*, S*, S*,)].

Part B:

(1.18 g, 1.8 mmol) of the product from Part A was dissolved in 50 mL ofmethanol, and to this was added 250 mg of 10% Palladium of Carbon whileunder a stream of nitrogen. The suspension was hydrogenated using 50psig of hydrogen for 20 hours. The contents were purged with nitrogenand filtered through celite, and concentrated in vacuo to yield 935 mgof Pentanamide, 2S-(amino)-N-[2R-hydroxy-3-[(3-methylpropyl)(4-methoxyphenylsulfonyl)amino]-1-S-(phenylmethyl)propyl]-3S-methyl-,which was used without further purification.

Part C:

(0.935 g, 1.8 mmol) of the amine from Part B was dissolved in 15 mL ofdioxane and to this was added (190 mg, 1.85 mmol) of 4-methylmorpholinefollowed by (0.315 g, 1.8 mmol) of chloroacetic anhydride. The reactionmixture was stirred under nitrogen atmosphere for 3 hours, concentratedin vacuo, and redissolved in ethyl acetate. The ethyl acetate solutionwas washed with 50 mL of 5% agueous KHSO4, saturated NaHCO₃, andsaturated NaCl solution, dried over MgSO₄, filtered and concentrated toyield 613 mg, (68% yield) of Pentanamide,2S-[(chloroacetyl)amino]-N-[2R-hydroxy-3-[(3-methylpropyl)(4-methoxyphenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3S-methyl-,after purification by silica gel chromatography using 1:1 hexane:ethylacetate.

Part D:

To a solution of the chloroacetamide from Part C; (673 mg, 1.10 mmol) in20 mL of tetrahydrofuran was added 5 mL of 50 wt % aqueous dimethylamineand the solution was stirred for 1 hour. The reaction was concentratedand the residue was redissolved in 50 mL of ethyl acetate and washedwith 25 mL of water. The ethyl acetate layer was dried over magnesiumsulfate, filtered and concentrated to yield a crude solid which waspurified by silica gel column chromatography using an eluant of 97:3dichloromethane:methanol to provide 400 mg of Pentanamide,2S-[[Dimethylamino) acetyl]amino]-N-[2R-hydroxy-3-[(3-methylpropyl)(4-methoxyphenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-3S-methyl-,

Example 13A

Preparation of Carbamic acid,[2R-hydroxy-3-[[(4-dimethylaminophenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,phenylmethyl ester

To a solution of 100 mg (0.19 mmol) of carbamic acid,[2R-hydroxy-3-[[(4-fluorophenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,phenylmethyl ester in 1 mL of pyridine was added 53 μL of triethylamineand 120 μL (p. 95 mmol) of 40% aqueous dimethylamine. After heating for24 hours at 100° C., the solution was cooled, ethyl acetate added, thenwashed with 5% citric acid, saturated sodium bicarbonate, dried overmagnesium sulfate, filtered and concentrated. The resulting solid wasrecrystallized from ethyl acetate/hexane to afford 10 mg of the desiredproduct; mass spectrum m/e=540 (M+H).

Example 13B

Preparation of Carbamic acid,[2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,3-pyridylmethyl ester

Part A:

A solution of N-benzyloxycarbonyl-3S-amino-1,2-S-epoxy-4-phenylbutane(50 g, 0.168 mol) and isobutylamine (246 g, 3.24 mol) in 650 mL ofisopropyl alcohol was refluxed for 1.25 hours. The solution was cooledto room temperature, concentrated in vacuo and then poured into 1 L ofstirring hexane whereupon the product crystallized from solution, wascollected and air dried to give 57.6 g ofN-[3S-benzyloxycarbonylamino-2R-hydroxy-4-phenyl]-N-isobutylamine, mp108-109.5° C. mass spectrum m/e=371 (M+H).

Part B:

The amine from part A (1.11 g, 3.0 mmol) and triethylamine (324 mg, 3.20mmol) in 20 mL of methylene chloride was treated with 715 mg (3.46 mmol)of 4-methoxybenzenesulfonyl chloride. The solution was stirred at roomtemperature for 6 hours, concentrated, dissolved in ethyl acetate, thenwashed with 1 N potassium hydrogen sulfate, saturated sodiumbicarbonate, brine, dried over magnesium sulfate, filtered andconcentrated to afford a clear oil. This was recrystallized from diethylether to afford 1.27 g of carbamic acid,[2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,phenylmethyl ester, mp 97-101° C., mass spectrum m/e=541 (M+H).

Part C:

A solution of 930 mg (3.20 mmol) of the product of part B in 30 mL ofmethanol was hydrogenated in the presence of 70 mg of a 10% palladium oncarbon catalyst under 40 psig for 17 hours, the catalyst was removed byfiltration, and the solution concentrated to afford 704 mg of[2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propylamine,mass spectrum m/e=407 (M+H), which was used directly in the next stepwithout purification.

Part D:

To a solution of 2.5 g (22.9 mmol) of 3-pyridylcarbinol in 100 mL ofanyhdrous acetonitrile was added 8.8 g (34.4 mmol) ofN,N′-disuccinimidyl carbonate and 5.55 mL (68.7 mmol) of pyridine. Thesolution was stirred for 1 hour and then concentrated in vacuo. Theresidue was dissolved in ethyl acetate, then washed with saturatedsodium bicarbonate, brine, dried over magnesium sulfate, filtered andconcentrated to afford 5.3 g of N-Hydroxysuccinimide-3-pyridylmethylcarbonate, mass spectrum m/e=251 (M+H), which was used directly in thenext step without purification.

Part E:

To a solution of the amine from C (2.87 g, 7.0 mmol) and 1.38 mL oftriethylamine in 24 mL of anhydrous methylene chloride was added asolution of 1.65 g (6.6 mmol) of N-hydroxysuccinimide-3-pyridylcarbonate from part D in 24 mL of methylene chloride. The solution wasstirred for 1 hour, 100 mL of methylene chloride added, then washed withsaturated sodium bicarbonate, brine, dried over sodium sulfate, filteredand concentrated to afford 3.69 g of crude product. Chromatography onsilica gel using 2% methanol/methylene chloride to afford 3.27 g ofcarbamic acid, [2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,3-pyridlmethyl ester, mass spectrum m/e=548 (M+Li).

Example 13C

Preparation of Carbamic acid,[2R-hydroxy-3-[(phenysulfonyl)(2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,3-pyridylmethyl ester

Part A:

A solution of N-benzyloxycarbonyl-3S-amino-1,2-S-epoxy-4-phenylbutane(50 g, 0.168 mol) and isobutylamine (246 g, 3.24 mol) in 650 mL ofisopropyl alcohol was refluxed for 1.25 hours. The solution was cooledto room temperature, concentrated in vacuo and then poured into 1 L ofstirring hexane whereupon the product crystallized from solution, wascollected and air dried to give 57.6 g ofN-[3S-benzyloxycarbonylamino-2R-hydroxy-4-phenyl]-N-isobutylamine, mp108-109.5° C., mass spectrum m/e=371 (M+H).

Part B:

The amine from part A (0.94 g, 2.5 mmol) and triethylamine (288 mg, 2.85mmol) in 20 mL of methylene chloride was treated with 461 mg (2.61 mmol)of benzenesulfonyl chloride. The solution was stirred at roomtemperature for 16 hours, concentrated, dissolved in ethyl acetate, thenwashed with 1 N potassium hydrogen sulfate, saturated sodiumbicarbonate, brine, dried over magnesium sulfate, filtered andconcentrated to afford a clear oil. This was recrystallized from diethylether and hexane to afford 0.73 g of carbamic acid,[2R-hydroxy-3-[(phenylsulfonyl)(2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, phenylmethyl ester, mp95-99° C., mass spectrum m/e=511 (M+H).

Part C:

A solution of 500 mg of carbamic acid, [2R-hydroxy-3-[(phenysulfonyl)(2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, phenylmethyl ester in20 mL of methanol was hydrogenated in the presence of 250 mg of a 10%palladium on carbon catalyst under 40 psig for 3 hours, the catalyst wasremoved by filtration, and the solution concentrated to afford 352 mg of[2R-hydroxy-3-[(phenylsulfonyl])2-methylpropyl)amino]-1S-(phenylmethyl)propylamine,mass spectrum m/e=377 (M+H), which was used directely in the next stepwithout purification.

Part D:

To a solution of 1.24 mmol of 5-norbornene-2,3-dicarboximidocarbonochloridate (Henklein, P., et. al., Synthesis 1987, 166-167) in 1mL of anhydrous methylene chloride, was added a solution of 43 μL (2.44mmol of 3-pyridylcarbinol and 129 μL (1.6 mmol) of pyridine in 1 mL ofmethylene chloride at 0° C. under a nitrogen atmosphere. After 4 hoursat room temperature, 150 mg (0.4 mmol) of[2R-hydroxy-3-[(phenylsulfonyl])2-methylpropyl)amino]-1S-(phenylmethyl)propylaminefrom Part C above was added and 100 μL of pyridine. After stirring for15 hours at room temperature, ethyl acetate was added, then washed with1N hydrochloric acid, saturated sodium bicarbonate, brine, dried overmagnesium sulfate, filtered and concentrated to afford 175 mg of crudeproduct. Chromatography over silica gel using 1% methanol/methylenechloride tp afford 69 mg of pure carbamic acid,[2R-hydroxy-3-[(phenylsulfonyl)(2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, 3-pyridylmethyl ester,mass spectrum m/e=512.2267 (M+H); calcd for C₂₇H₃₃N₃O₅S, 512.2219.

Example 13D

Preparation of Carbamic acid, [2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, 3-pyridylmethyl ester,N-oxide

To a solution of 211 mg (0.39 mmol) of carbamic acid, *2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(Phenylmethyl)propyl]-,3-pyridylmethyl ester in 5 mL of methylene chloride at O C was added 500mg of 50% 3-chloroperbenzoic acid. After stirring at room temperaturefor 1 hour, ethyl acetate was added, the solution washed with saturatedsodium bicarbonate, 0.2N ammonium hydroxide solution and brine, driedover magnesium sulfate, filtered and concentrated to afford 200 mg ofcrude product. This was chromatographed on C18 reverse phase materialusing 20-40% acetonitrile/water, then 100% acetonitrile to afford 90 mgof the desired product, which was then recrystallized from ethylacetate/isooctane to yiel 34 mg of pure carbamic acid,[2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, 3-pyridylmethyl ester,N-oxide; mass spectrum m/e=564 (M+Li).

Example 13E

Preparation of Carbamic acid,[2R-hydroxy-3-[[(4-hydroxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-,3-pyridylmethyl ester

Part A

A solution of 0.98 g (1.85 mmol) of carbamic acid,[2R-hydroxy-3-[[(4-fluorophenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-phenylmethyl ester in3.8 mL of anhydrous DMF was added to 22 mg (7.4 mmol) of 80% sodiumhydride in 2 mL of DMF. To this mixture was added 0.40 g (3.7 mmol) ofbenzyl alcohol. After 2 hours, the solution was cooled to 0 C, wateradded, and then ethyl acetate. The organic layer was washed with 5%cirtic acid, saturated sodium bicarbonate and brine, dried overmagnesium sulfate, filtered and concentrated to afford 0.90 g of crudematerial. This was chromatographed on basic alumina using 3%methanol/methylene chloride to afford 0.70 g of2R-hydroxy-3-[(2-methylpropyl)(4-hydroxyphenyl)sulfonyl]amino-1S-(phenylmethyl)propylamine, cycliccarbamate; mass spectrum m/e=509(M+H).

Part B

To a solution of 0.65 g (1.28 mmol) of the cyclic carbamate from part Ain 15 mL of ethanol, was added 2.6 mL (6.4 mmol) of 2.5N sodiumhydroxide solution. After 1 hour at reflux, 4 mL of water was added andthe solution refluxed for an additional eight hours. The volatiles wereremoved, ethyl acetate added, and washed with water, brine, dried overmagnesium sulfate, filtered and concentrated to afford 550 mg ofcrude2R-hydroxy-3-[(2-methylpropyl)(4-hydroxyphenyl)sulfonyl]amino-1S-(phenylmethyl)propylamine.

Part C

A solution of crude 2R-hydroxy-3-[(2-methylpropyl)(4-benzyloxyphenyl)sulfonyl]amino-1S-(phenylmethyl)propylamine in 10 mLof ethanol was hydrogenated in the presence of 500 mg of a 10% palldiumon carbon catalyst under 50 psig of hydrogen for 2 hours. The catalystwas removed by filtration and the solvent removed in vacuo to afford 330mg of 2R-hydroxy-3-[(2-methylpropyl) (4-hydroxyphenyl)sulfonyl]amino-1-S-(phenylmethyl)propylamine, mass spectrum m/e=393(M+H).

To a solution of 320 mg (0.82 mmol) of the amine from part C in 6 mL ofDMF, was added 192 mg (0.76 mmol) ofN-hydroxysuccinimide-3-pyridylmethyl carbonate. After 15 hours at roomtemperature, the DMF was removed in vacuo, ethyl acetate added, washedwith water, brine, dried with magnesium sulfate, filtered andconcentrated to afford 390 mg of crude material. Chromatography onsilica gel using 50-80% ethyl acetate/hexane afforded 180 mg of carbamicacid, [2R-hydroxy-3-[[(4-hydroxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, 3-pyridylmethyl ester,mass spectrum m/e=528 (M+H).

Example 13F

Preparation of Carbamic acid, [2R-hydroxy-3-[[(4-methoxyphenyl)sulfonyl](2-methylpropyl)amino]-1S-(phenylmethyl)propyl]-, 5-pyrimidylmethylester

To a solution of 9.5 mg (0.09 mmol) of 5-pyrimidylcarbinol in 1 mL ofanhydrous acetonitrile at room temperature, was added 24 mg (0.99 mmol)of N,N′-disuccinimidyl carbonate and 19.1 μL (0.24 mmol) of pyridine.After stirring for 5 hours, 32 mg (0.08 mmol) of2R-hydroxy-3-[(2-methylpropyl)(4-methoxyphenyl)sulfonyl]amino-1S-(phenylmethyl)propylamine was addedand the solution stirred for 48 hours. After concentration in vacuo,methylene chloride was added, then washed with a 1:1 mixture ofsaturated sodium bicarbonate and brine, dried over magnesium sulfate,filtered and concentrated to give 27 mg of crude product. Chromatographyon silica gel using 2% methanol/methylene chloride afforded 22 mg of thedesired product, mass spectrum m/e=543 (M+H).

Example 14

Preparation of phenylmethyl[3-amino-1S-[[2R-hydroxy-3-[(3-propyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)amino]-carbonyl]-3-oxopropyl]carbamate

Phenylmethyl[2R-hydroxy-3-[(3-propyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)propyl]-carbamate (200 mg, 0.40mmol) was deprotected by hydrogenation over 10% palladium on carbon andthe resulting free amine was coupled with N-CBZ-L-asparagine (157 mg,0.42 mmol) in the presence of N-hydroxybenzotriazole (114 mg, 0.84 mmol)and EDC (130 mg, 0.67 mmol) to givephenylmethyl[3-amino-1S-[[2R-hydroxy-3-[(3-propyl)(phenylsulfonyl)amino]-1S-(phenylmethyl)amino]carbonyl]-3-oxopropyl]carbamateas a solid. Anal. Calcd for C₃₁H₃₈N₄O₇S.0.2H₂O: C, 60.61; H,6.30;N,9.12. Found: C,60.27; H,6.16; N,8.93.

Example 15A

Preparation of N1-[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-N4-methyl-1S-(phenylmethyl)propyl]-2S-[(2-quinolinylcarbonyl)amino]butanediamide

Part A

N2-[(1,1-dimethylethoxy)carbonyl]-N-methyl-L-asparagine was preparedfrom Boc-L-aspartic acid alphabenzyl ester (1.0 g, 3.09 mmol),methylamine.HCl (209 mg, 3.09 mmol), EDC(711 mg, 3.7 mmol),1-hydroxybenzotriazole (627 mg, 4.63 mmol), and N-methylmorpholine (0.7mL, 6.3 mmol), in DMF (20 mL). After stirring overnight at r.t., thereaction mixture was diluted with ethyl acetate, washed with water, sat.sodium bicarbonate, 5% citric acid, brine, dried over magnesium sulfateand concentrated to an oil. The oil was taken up in 20 mL dry ethanol,and hydrogenated in the presence of 10% w/w of 10% Pd on C atatmospheric pressure and room temperature overnight. The mixture wasfiltered through Celite and concentrated to a white solid foam, 670 mg.

Part B

A solution of phenylmethyl [2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1-S-(phenylmethyl)-propyl]carbamate (310 mg, 0.59mmol) in methanol (10 mL) was hydrogenated over 10% palladium on carbonfor 3 h., filtered through diatomaceous earth and concentrated to givethe product as an oil (214 mg). This free amine (208 mg, 0.53 mmol) wascoupled with N2-[(1,1-dimethylethoxy)-carbonyl]-N-methyl-L-asparagine(137 mg, 0.56 mmol) in the presence of N-hydroxybenzotriazole (102 mg,0.76 mmol) and EDC (130 mg, 0.67 mmol) to yield 290 mg ofN1[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-N4-methyl-1S-(phenylmethyl)propyl]-2S-[(1,1-dimethylethoxy-carbonyl)amino]butanediamide.

Part C

N1[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-N4-methyl-1S-(phenylmethyl)propyl]-2S-[(1,1-dimetylethoxycarbonyl)-amino]butanediamide(270 mg, 0.43 mmol) was stirred in 4N HCl in dioxane (5 mL) atr.t. for 0.5 h. Solvent and excess reagent were evaporated to dryness.The product was dried in vacuo. This material (125 mg, 0.225 mmol) wasthen reacted with 2-quinoline carboxylic acid N-hydroxysuccimide ester(61 mg, 0.225 mmol), N-methylmorpholine (50 μL, 0.45 mmol) in methylenechloride (2 mL) for 3 h. The product N1[2R-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-N4-methyl-1S-(phenylmethyl)propyl]-2S-[(2-quinolinylcarbonyl)-amino]butanediamide was purified by silica gel chromatography. Anal. Calcd forC₃₆H₄₃N₅O₆S.0.2H₂O: C,63.83; H,6.45; N,10.34. Found: C,63.64; H,6.40;N,10.34.

Example 15B

Following the procedures set forth above, the following compound wasalso prepared:

Preparation of Carbamic acid, [3-[[2-hydroxy-3-[(3-methylbutyl)(phenylsulfonyl)amino]-1-(phenylmethyl)propyl]amino]-2-methyl-3-oxopropyl]-,(4-methoxyphenyl)methyl ester, [1S-[1R*(S*),2S*]]

Thus, 4.10 g, (7.8 mmol), of Carbamic acid,[2R-hydroxy-3-[(3-methylbutyl)(phenylsulphonyl)amino]-1S-(phenylmethyl)propyl]-, phenylmethyl ester,[R-(R*,S*)]- was hydrogenated in a solution of methanol and ethanolusing catalytic Pd/C 10% at 50 psig hydrogen for 3 hours. The catalystwas filtered and the solvents removed in vacuo to yield 3.0 grams offree amine.

In a separate flask, 2.09 g, (7.8 mmol), of N-Moz-AMBA was added to 10mL of dimethylformamide and 1.58 g, (1.5 equiv.), ofN-hydroxybenzoltriazole and the solution was cooled to 5 degrees C. Tothis solution was added 1.49 g, (7.8 mmol), of EDC and the solutionstirred for 30 min. To this was added the free amine in 10 mL ofdimethylformamide, and the reaction was stirred for 20 hours. Thesolvent was removed by evaporation and the crude material waspartitioned between ethyl acetate and saturated aqueous sodiumbicarbonate. The ethyl acetate layer was washed with 5% potassiumhydrogen sulfate and brine, dried over magnesium sulfate, filtered andconcentrated to yield 2.58 grams of pure product after recrystallizationfrom ethyl acetate, ether, and hexanes, 52% yield.

Example 16

Following the procedures of Examples 1-15, the compounds shown in Table3 were prepared. Utilizing the general and specific procedures ofExamples 1-15 and the remainder of the specification, the compoundsshown in Tables 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 14A could beand/or were prepared. Table 5A also provides calculated versus foundmass spectroscopy results for the compounds disclosed therein. Tables5B, 15A, 15B, and 16 disclose IC₅₀, EC₅₀ and/or TC₅₀ values for thecompounds referenced therein, respectively.

TABLE 3

Entry No. R R¹ R³ R⁴ 1 Cbz t-Butyl i-Amyl Methyl 2 N,N-Dimethyl- t-Butyli-Amyl Methyl glycine 3 Cbz i-Propyl i-Amyl Phenyl 4 Cbz sec-Butyli-Amyl Phenyl 5 Cbz CH₂C(O)NH₂ n-Propyl Phenyl 6 N-Methylglycine t-Butyli-Amyl Phenyl 7 Cbz t-Butyl i-Butyl Phenyl 8 N,N-Dimethyl- t-Butyli-Amyl Phenyl glycine 9 N-Methylglycine t-Butyl i-Amyl Phenyl 10N,N-Dimethyl- t-Butyl i-Butyl (4-OCH₃)Phenyl glycine 11 N-Methylglycinet-Butyl i-Butyl (4-OCH₃)Phenyl

TABLE 4

Entry No. R R³ R⁴ 1 Cbz^(a) CH₃ n-Butyl 2 Cbz i-Butyl CH₃ 3 Cbz i-Butyln-Butyl 4 Qb i-Butyl n-Butyl 5 Cbz i-Propyl n-Butyl 6 Q i-Propyl n-Butyl7 Cbz C₆H₅ n-Butyl 8 Cbz

n-Butyl 9 Cbz

n-Butyl 10 Q

n-Butyl 11 Cbz

n-Butyl 12 Cbz i-Butyl n-Propyl 13 Cbz i-Butyl —CH₂CH(CH₃)₂ 14 Cbz

n-Butyl 15 Cbz

i-Propyl 16 Cbz

—CH₂CH₂CH(CH₃)₂ 17 Cbz i-Butyl —CH₂CH₃ 18 Cbz i-Butyl —CH(CH₃)₂ 19 Cbzi-Butyl

20 Q -Butyl

21 Cbz

—(CH₂)₂CH(CH₃)₂ 22 Cbz (CH₂)₂CH(CH₃)₂ —CH(CH₃)₂ 23 Q i-Butyl —CH(CH₃)₂24 Cbz i-Butyl —C(CH₃)₃ 25 Q i-Butyl —C(CH₃)₃ 26 Cbz

—C(CH₃)₃ 27 Q

—C(CH₃)₃ 28 Cbz —(CH₂)₂CH(CH₃)₂ —C(CH₃)₃ 29 Q —(CH₂)₂CH(CH₃)₂ —C(CH₃)₃30 Cbz —CH₂C₆H₅ —C(CH₃)₃ 31 Q —CH₂C₆H₅ —C(CH₃)₃ 32 Cbz —(CH₂)₂C₆H₅—C(CH₃)₃ 33 Cbz —(CH₂)₂C₆H₅ —C(CH₃)₃ 34 Cbz n-Butyl —C(CH₃)₃ 35 Cbzn-Pentyl —C(CH₃)₃ 36 Cbz n-Hexyl —C(CH₃)₃ 37 Cbz

—C(CH₃)₃ 38 Cbz —CH₂C(CH₃)₃ —C(CH₃)₃ 39 Q —CH₂C(CH₃)₃ —C(CH₃)₃ 40 Cbz

—C(CH₃)₃ 41 Cbz —CH₂C₆H₅OCH₃ (para) —C (CH₃)₃ 42 Cbz

—C(CH₃)₃ 43 Cbz

—C(CH₃)₃ 44 Cbz —(CH₂)₂C(CH₃)₃ —C(CH₃)₃ 45 Q —(CH₂)₂C(CH₃)₃ —C(CH₃)₃ 46Cbz —(CH₂)₄OH —C(CH₃)₃ 47 Q —(CH₂)₄OH —C(CH₃)₃ 48 Q

—C(CH₃)₃ 49 Q

—C(CH₃)₃ 50 Cbz —CH₂CH(CH₃)₂ —C₆H₅ 51

—CH₂CH(CH₃)₂ —C₆H₅ 52

—CH₂CH(CH₃)₂ —C₆H₅ 53

—CH₂CH(CH₃)₂ —C₆H₅ 54

—CH₂CH(CH₃)₂ —C₆H₅ 55

—CH₂CH(CH₃)₂ —C₆H₅ 56

—CH₂CH(CH₃)₂ —C₆H₅ 57

—CH₂CH(CH₃)₂ —C₆H₅ 58

—CH₂CH(CH₃)₂ —C₆H₅ 59

—CH₂CH(CH₃)₂ —C₆H₅ 60

—CH₂CH(CH₃)₂ —C₆H₅ 61

—CH₂CH(CH₃)₂ —C₆H₅ 62

—CH₂CH(CH₃)₂ —C₆H₅ 63

—CH₂CH(CH₃)₂ —C₆H₅ 64

—CH₂CH(CH₃)₂ —C₆H₅ 65

—CH₂CH(CH₃)₂ —C₆H₅ 66

—CH₂CH(CH₃)₂ —C₆H₅ 67

—CH₂CH(CH₃)₂ —C₆H₅ 68

—CH₂CH(CH₃)₂ —C₆H₅ 69

—CH₂CH(CH₃)₂ —C₆H₅ 70 Q —CH₂Ph —Ph 71 Q

—Ph 72 Q

—Ph 73 Q

—Ph 74 Q

—Ph 75 Q

—Ph 76 Q —CH₂CH═CH₂ —Ph 77 Q

—Ph 78 Q

—Ph 79 Q —CH₂CH₂Ph —Ph 80 Q —CH₂CH₂CH₂CH₂OH —Ph 81 Q —CH₂CH₂N(CH₃)₂ —Ph82 Q

—Ph 83 Q —CH₃ —Ph 84 Q —CH₂CH₂CH₂SCH₃ —Ph 85 Q —CH₂CH₂CH₂S(O)₂CH₃ —Ph 86Q —CH₂CH₂CH₂CH(CH₃)₂

87 Q —CH₂CH₂CH(CH₃)₂

88 Q —CH₂CH₂CH(CH₃)₂ —CH₂CH₂CH₃ 89 Q —CH₂CH₂CH₂CH(CH₃)₂ —CH₃ 90 Q—CH₂CH₂CH(CH₃)₂

91 Q —CH₂CH₂CH(CH₃)₂

92 Q —CH₂CH₂CH(CH₃)₂

93 Q —CH₂CH₂CH(CH₃)₂

94 Q —CH₂CH₂CH(CH₃)₂

95 Q —CH₂CH₂CH(CH₃)₂

96 Q —CH₂CH₂CH(CH₃)₂

97 Q —CH₂CH₂CH(CH₃)₂

98 Q —CH₂CH₂CH(CH₃)₂

99 Q —CH₂CH₂CH(CH₃)₂

100 Q —CH₂CH₂CH(CH₃)₂

101 Q —CH₂CH₂CH(CH₃)₂

102 Q —CH₂CH₂CH(CH₃)₂

103 Q —CH₂CH(CH₃)₂

104 Q —CH₂CH(CH₃)₂

105 Q —CH₂CH(CH₃)₂

106 Q —CH₂CH₂CH₃

107 Q —CH₂CH₂CH₂CH₃

^(a)benzyloxycarbonyl ^(b)2-quinolinylcarbonyl

TABLE 5

Entry A R³ R⁴ 1 Cbz—Val i-amyl —C₆H₅ 2 Cbz—Leu i-amyl —C₆H₅ 3 Cbz—Ilei-amyl —C₆H₅ 4 Ac-D-homo-Phe i-Bu methyl 5 Qui-Orn(g-Cbz)

—C₆H₅ 6 Cbz-Asn —CH₂CH═CH₂ —C₆H₅ 7 Acetyl-t-BuGly i-amyl —C₆H₅ 8Acetyl-Phe i-amyl —C₆H₅ 9 Acetyl-Ile i-amyl —C₆H₅ 10 Acetyl-Leu i-amyl—C₆H₅ 11 Acetyl-His i-amyl —C₆H₅ 12 Acetyl-Thr i-amyl —C₆H₅ 13Acetyl-NHCH(C(CH₃)₂(SCH₃))C(O)— i-amyl —C₆H₅ 14 Cbz-Asn i-amyl —C₆H₅ 15Cbz-Ala i-amyl —C₆H₅ 16 (N,N-dimethylglycinyl)Val i-amyl —C₆H₅ 17(N-methylglycinyl)Val i-amyl —C₆H₅ 18 (N,N-dimethylglycinyl)Ile i-amyl—C₆H₅ 19 (N-methylglycinyl)Ile i-amyl —C₆H₅ 20 Cbz-Ala i-amyl —C₆H₅ 21Cbz-beta-cyanoAla i-amyl —C₆H₅ 22 Cbz-t-BuGly i-amyl —C₆H₅ 23 Q-t-BuGlyi-amyl —C₆H₅ 24 Q-SCH₃CyS i-amyl —C₆H₅ 25 Cbz-SCH₃Cys i-amyl —C₆H₅ 26Q-Asp i-amyl —C₆H₅ 27 Cbz-(NHCH(C(CH₃)₂(SCH₃))C(O)— i-amyl —C₆H₅ 28Cbz-EtGly i-amyl —C₆H₅ 29 Cbz-PrGly i-amyl —C₆H₅ 30 Cbz-Thr i-amyl —C₆H₅31 Q-Phe i-amyl —C₆H₅ 32 Cbz-Phe i-amyl —C₆H₅ 33 CH₂═CHCH₂O)C═O) i-Butyl—C₆H₄(4-OCH₃)

TABLE 5A

MASS MEASUREMENT CALC Entry R³ R⁴ R⁷ MOL FORM M + H FOUND  1

C₂₇H₃₈N₂O₅S 503.2661 503.2624  2

C₂₈H₄₀N₂O₅S 517.2736 517.2777  3

C₂₉H₄₂N₂O₅S 531.2893 531.2916  4

C₃₂H₄₀N₂O₅S 565.2736 565.2731  5

C₃₀H₃₅N₃O₅S 550.2376 550.2427

MASS MEASUREMENT Entry R³ R⁴ R⁷ MOL FORM CALC FOUND  6

C₃₀H₃₈N₂O₅S 539 (M + H) 539  7

C₂₉H₃₆N₂O₅S ? ?  8 C₃₀H₃₈N₂O₅S 539.2580 (M + H) 539.2591

MASS MEASUREMENT CALC Entry R³ R⁴ R⁷ MOL FORM (M + H) FOUND  9

C₂₇H₃₃N₃O₅S 512.2219 512.2271 10

C₂₈H₃₅N₃O₅S 526.2376 526.2388 11

C₂₇H₃₃N₃O₅S 512.2219 526.2287 12

C₂₈H₃₃N₂O₅ClS 545.1877 545.1887 13

C₃₀H₃₈N₂O₅S 539.2580 539.2592 14

C₃₁H₄₀N₂O₅S 553.2736 553.2714 15

C₃₀H₃₈N₂O₅S 539.2580 539.2632 16

C₃₀H₃₈N₂O₅S 539 (M + H) 539

MASS MEASUREMENT Entry R³ R⁴ R⁷ MOL FORM CALC FOUND 17

C₂₉H₃₆N₂O₇S₂ 589.2042 (M + H) 589.2086 18

C₂₉H₃₆N₂O₇S₂ 595.2124 (M + Li) 595.2103 19

C₂₉H₃₆N₂O₇S₂ 595.2124 (M + Li) 595.2191 20

C₃₀H₃₈N₂O₇S₂ 609.2281 (M + Li) 609.2313 21

C₃₀H₃₈N₂O₇S₂ 603.2199 (M + H) 603.2247 22

C₃₀H₃₈N₂O₇S₂ 603.2199 (M + H) 603.2266

EXACT MASS MEASUREMENT CALC Entry R³ R⁴ R⁷ MOL FORM (M + H) FOUND 23

24

C₂₇H₃₂N₂O₄S 481.2161 481.2213 25

C₂₈H₃₅N₂O₅S 511.2267 511.2319 26

C₂₉H₃₆N₂O₅S 525.2423 525.2469 27

C₂₉H₃₆N₂O₅S 525.2428 525.2464 28

C₂₉H₃₆N₂O₅S 525.2423 525.2432 29

C₂₉H₃₆N₂O₆S 541.2372 541.2332 30

C₂₉H₃₆N₂O₆S 541.2372 541.2355 31

C₂₉H₃₆N₂O₆S 541.2372 541.2329

TABLE 5B Table Entry IC₅₀ (μM) or % inhibition 1A 3 0.02 5A 1 D.04 5A 30.02 5A 4 0.01 5A 5 0.026 5A 6 0.023 5A 7 0.007 5A 9 0.067 5A 11 0.0185A 12 0.006 5A 13 0.0098 5A 14 0.049 5A 16 0.008 5A 17 59% @ 10 μM 5A 180.13 5A 19 0.092 5A 20 85% @ 1 μM 5A 22 63% @ 1 μM 5A 24 0.047 5A 250.014 5A 26 0.005 5A 28 0.015 5A 29 0.19 5A 30 0.03 5A 31 0.02

TABLE 6

Entry R¹ 1 CH₂SO₂CH₃ 2 (R)—CH(OH)CH₃ 3 CH(CH₃)₂ 4 (R,S)CH₂SOCH₃ 5CH₂SO₂NH₂ 6 CH₂SCH₃ 7 CH₂CH(CH₃)₂ 8 CH₂CH₂C(O)NH₂ 9 (S)—CH(OH)CH₃ 10—CH₂C≡C—H

TABLE 7

Entry R² A 1 n-Bu Cbz-Asn 2 cyclohexylmethyl Cbz-Asn 3 n-Bu Boc 4 n-BuCbz 5 C₆H₅CH₂ Boc 6 P—F—C₆H₅CH₂ Cbz 7 C₆H₅CH₂ benzoyl 8 cyclohexylmethylCbz 9 n-Bu Q-Asn 10 cyclohexylmethyl Q-Asn 11 C₆H₅CH₂ Cbz-Ile 12 C₆H₅CH₂Q-Ile 13 P—F—C₆H₅CH₂ Cbz-t-BuGly 14 C₆H₅CH₂ Q-t-BuGly 15 C₆H₅CH₂ Cbz-Val16 C₆H₅CH₂ Q-Val 17 2-naphthylmethyl Cbz-Asn 18 2-naphthylmethyl Q-Asn19 2-naphthylmethyl Cbz 20 n-Bu Cbz-Val 21 n-Bu Q-Val 22 n-Bu Q-Ile 23n-Bu Cbz-t-BuGly 24 n-Bu Q-t-BuGly 25 p-F(C₆H₄)CH₂ Q-Asn 26 p-F(C₆H₄)CH₂Cbz 27 p-F(C₆H₄)CH₂ Cbz-Asn 28 C₆H₅CH₂ Cbz-propargylglycine 29 C₆H₅CH₂Q-propargylglycine 30 C₆H₅CH₂ acetylpropargylglycine

TABLE 8

Entry R³ R⁴ 1 —CH₂CH(CH₃)₂ —C(CH₃)₂ 2 —CH₂CH₂CH(CH₃)₂

3 —CH₂CH₂CH(CH₃)₂

4 —CH₂CH₂CH(CH₃)₂

5 —CH₂CH₂CH(CH₃)₂

TABLE 9

Entry R R¹ 1

—CH₃ 2

—CH₃ 3

—CH(CH₃)₂ 4

—CH(CH₃)₂ 5

—C(CH₃)₃ 6

—CH₃ 7

—CH₃ 8

—CH₃ 9

—CH₃ 10

—CH₃ 11

—CH₃ 12

—CH₃ 13

—CH₃ 14

—CH₃ Entry 15

16

TABLE 10

Entry R¹ R¹′ R¹″ R 1 H H H

2 H H H

3 H CH₃ H

4 H CH₃ CH₃

5 H H CO₂CH₃

6 H H H

7 H H H

8 H H CONH₂ Cbz 9 H H CONH₂ 2-quinolinylcarbonyl

TABLE 11

Entry R R′ X 1 R═H R′═H X═H 2 R═Me R′═Me X═H 3 R═H R′═Me X═H 4 R═MeR′═Me X═F 5 R═H R′═Me X═F 6 R═Cbz R′═Me X═H 7 R═H R′═Bz X═H 8 R + R′ =pyrrole X═H

TABLE 12

Entry Acyl Group (R) 1 benzyloxycarbonyl 2 tert-butoxycarbonyl 3 acetyl4 2-quinoylcarbonyl 5 phenoxyacetyl 6 benzoyl 7 methyloxaloyl 8 pivaloyl9 trifluoracetyl 10 bromoacetyl 11 hydroxyacetyl 12 morpholinylacetyl 13N,N-dimethylaminoacetyl 14 N-benzylaminoacetyl 15 N-phenylaminoacetyl 16N-benzyl-N-methylaminoacetyl 17 N-methyl-N-(2-hydroxyethyl)aminoacetyl18 N-methylcarbamoyl 19 3-methylbutyryl 20 N-isobutylcarbamoyl 21succinoyl(3-carboxypropionyl) 22 carbamoyl 23 N-(2-indanyl)aminoacetyl

TABLE 13

Entry R³ R⁴ 1 —CH₃ -n-Butyl 2 -i-Butyl —CH₃ 3 -i-Butyl -n-Butyl 4-i-Propyl -n-Butyl 5 —C₆H₅ -n-Butyl 6

-n-Butyl 7

-n-Butyl 8

-n-Butyl 9 -i-Butyl -n-Propyl 10 -i-Butyl —CH₂CH(CH₃)₂ 11

-n-Butyl 12

-i-Propyl 13

—CH₂CH₂CH(CH₃)₂ 14 i-Butyl —CH₂CH₃ 15 i-Butyl —CH(CH₃)₂ 16 i-Butyl

17

—(CH₂)₂CH(CH₃)₂ 18 (CH₂)₂CH(CH₃)₂ —CH(CH₃)₂ 19 i-Butyl —CH(CH₃)₂ 20i-Butyl —C(CH₃)₃ 21

—C(CH₃)₃ 22 —(CH₂)₂CH(CH₃)₂ —C(CH₃)₃ 23 —CH₂C₆H₅ —C(CH₃)₃ 24 —(CH₂)₂C₆H₅—C(CH₃)₃ 25 n-Butyl —C(CH₃)₃ 26 n-Pentyl —C(CH₃)₃ 27 n-Hexyl —C(CH₃)₃ 28

—C(CH₃)₃ 29 —CH₂C(CH₃)₃ —C(CH₃)₃ 30

—C(CH₃)₃ 31 —CH₂C₆H₅OCH₃ (para) —C(CH₃)₃ 32

—C(CH₃)₃ 33

—C(CH₃)₃ 34 —(CH₂)₂C(CH₃)₃ —C(CH₃)₃ 35 —(CH₂)₄OH —C(CH₃)₃ 36

—C(CH₃)₃ 37

—C(CH₃)₃ 38 —CH₂CH(CH₃)₂ —C₆H₅ 39 i-amyl —CH₂C(CH₃)₃ 40

—CH₂C(CH₃)₃ 41

—CH₂C(CH₃)₃ 42 i-butyl —CH₂C(CH₃)₃ 43 —CH₂Ph —Ph 44

—Ph 45

—Ph 46

—Ph 47

—Ph 48

—Ph 49 —CH₂CH═CH₂ —Ph 50

—Ph 51

—Ph 52 —CH₂CH₂Ph —Ph 53 —CH₂CH₂CH₂CH₂OH —Ph 54 —CH₂CH₂N(CH₃)₂ —Ph 55

—Ph 56 —CH₃ —Ph 57 —CH₂CH₂CH₂SCH₃ —Ph 58 —CH₂CH₂CH₂S(O)₂CH₃ —Ph 59—CH₂CH₂CH(CH₃)₂

60 —CH₂CH₂CH(CH₃)₂

61 —CH₂CH₂CH(CH₃)₂ —CH₂CH₂CH₃ 62 —CH₂CH₂CH(CH₃)₂ —CH₃ 63 —CH₂CH₂CH(CH₃)₂

64 —CH₂CH₂CH(CH₃)₂

65 —CH₂CH₂CH(CH₃)₂

66 —CH₂CH₂CH(CH₃)₂

67 —CH₂CH₂CH(CH₃)₂

68 —CH₂CH₂CH(CH₃)₂

69 —CH₂CH₂CH(CH₃)₂

70 —CH₂CH₂CH(CH₃)₂

71 —CH₂CH₂CH(CH₃)₂

72 —CH₂CH₂CH(CH₃)₂

73 —CH₂CH₂CH(CH₃)₂

74 —CH₂CH₂CH(CH₃)₂

75 —CH₂CH(CH₃)₂

76 —CH₂CH(CH₃)₂

77 —CH₂CH(CH₃)₂

78 —CH₂CH(CH₃)₂

79 —CH₂CH₂CH₃

80 —CH₂CH₂CH₂CH₃

^(a)benzyloxycarbonyl ^(b)2-quinolinylcarbonyl

TABLE 14

Entry R¹ R³ 1 C(CH₃)₃ CH₂CH₂CH(CH₃)₂ 2 CH₂C≡CH CH₂CH₂CH(CH₃)₂ 3C(CH₃)₂(SCH₃) CH₂CH₂CH(CH₃)₂ 4 C(CH₃)₂(S[O]CH₃) CH₂CH₂CH(CH₃)₂ 5C(CH₃)₂(S[O]₂CH₃) CH₂CH₂CH(CH₃)₂ 6 C(CH₃)₃ CH₂CH(CH₃)₂ 7 C(CH₃)₃

8 CH(CH₃)₂ CH₂CH(CH₃)₂ 9 CH(CH₂CH₃)(CH₃) CH₂CH(CH₃)₂

TABLE 14A

Entry 1 C(CH₃)SCH₃ CH₂CH₂CH(CH₃)₂

Example 17

The compounds of the present invention are effective HIV proteaseinhibitors. Utilizing an enzyme assay as described below, the compoundsset forth in the examples herein disclosed inhibited the HIV enzyme. Thepreferred compounds of the present invention and their calculated IC₅₀(inhibiting concentration 50%, i.e., the concentration at which theinhibitor compound reduces enzyme activity by 50%) values are shown inTable 16. The enzyme method is described below. The substrate is2-Ile-Nle-Phe(p-NO₂)-Gln-ArgNH₂. The positive control is MVT-101[Miller, M. et al., Science, 246, 1149 (1989)] The assay conditions areas follows:

Assay buffer: 20 mM sodium phosphate, pH 6.4 20% glycerol  1 mM EDTA  1mM DTT  0.1% CHAPS

The above described substrate is dissolved in DMSO, then diluted 10 foldin assay buffer. Final substrate concentration in the assay is 80 μM.

HIV protease is diluted in the assay buffer to a final enzymeconcentration of 12.3 nanomolar, based on a molecular weight of 10,780.

The final concentration of DMSO is 14% and the final concentration ofglycerol is 18%. The test compound is dissolved in DMSO and diluted inDMSO to 10x the test concentration; 10 μl of the enzyme preparation isadded, the materials mixed and then the mixture is incubated at ambienttemperature for 15 minutes. The enzyme reaction is initiated by theaddition of 40 μl of substrate. The increase in fluorescence ismonitored at 4 time points (0, 8, 16 and 24 minutes) at ambienttemperature. Each assay is carried out in duplicate wells.

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples.

TABLE 15A Entry Compound IC₅₀(nanomolar) 1

16 2

1.5 3

1.4 4

27 5

19 6

10 7

3.6 8

4.2 9

3.5 10

100 11

81 12

20

TABLE 15B Ex. Table Entry IC₅₀ (μM) or % inhib 6 1a 1 0.011 6 1a 2 0.0106 1a 3 38% @ 1 μM, 79% @ 10 μM 6 1a 4 0.016 6 1a 5 0.10 6 1a 6 36% @ 10μM 6 1a 7 0.0096 6 1a 39 0.016 6 1a 40 0.21 6 1a 41 24% @ 1 μM, 74% @ 10μM 6 1a 50 42% @ 1 μM, 89% @ 10 μM 6 1a 51 31% @ 1 μM, 76% @ 10 μM 6 1a52 39% @ 1 μM, 81% @ 10 μM 6 1a 53 0.049 6 1a 54 0.0028 6 1a 55 0.10 61a 56 0.0036 16 3 1 0.081 16 3 2 38% @ 0.1 μM, 90% @ 1.0 μM 16 3 40.0024 16 3 6 0.0018 16 3 8 0.003 16 3 10 0.0025 16 3 12 0.0016 16 4 1020.0015 16 5 1 0.0014 16 5 14 0.0022 16 5 22 0.0018 16 5 33 0.0044 16 534 0.0020 16 7 31 0.0028 16 7 32 0.0015 16 11  1 0.13 16 11  9 41% @ 0.1μM, 86% @ 1 μM 16 12  10 0.0033 16 14  3 0.0049 16 14  10 0.0032

Example 18

The effectiveness of the compounds listed in Tables 15A and 15B weredetermined in the above-described enzyme assay and in a CFM cell assay.

The HIV inhibition assay method of acutely infected cells is anautomated tetrazolium based colorimetric assay essentially that reportedby Pauwles et al, J. Virol. Methods, 20, 309-321 (1988). Assays wereperformed in 96-well tissue culture plates. CEM cells, a CD4⁺ cell line,were grown in RPMI-1640 medium (Gibco) supplemented with a 10% fetalcalf serum and were then treated with polybrene (2 μg/ml). An 80 μlvolume of medium containing 1×10⁴ cells was dispensed into each well ofthe tissue culture plate. To each well was added a 100 μl volume of testcompound dissolved in tissue culture medium (or medium without testcompound as a control) to achieve the desired final concentration andthe cells were incubated at 37° C. for 1 hour. A frozen culture of HIV-1was diluted in culture medium to a concentration of 5×10⁴ TCI₅₀ per ml(TCID₅₀=the dose of virus that infects 50% of cells in tissue culture),and a 20 μL volume of the virus sample (containing 1000 TCID₅₀ of virus)was added to wells containing test compound and to wells containing onlymedium (infected control cells). Several wells received culture mediumwithout virus (uninfected control cells). Likewise, the intrinsictoxicity of the test compound was determined by adding medium withoutvirus to several wells containing test compound. In summary, the tissueculture plates contained the following experiments:

Cells Drug Virus 1. + − − 2. + + − 3. + − + 4. + + +

In experiments 2 and 4 the final concentrations of test compounds were1, 10, 100 and 500 μg/ml. Either azidothymidine (AZT) or dideoxyinosine(ddI) was included as a positive drug control. Test compounds weredissolved in DMSO and diluted into tissue culture medium so that thefinal DMSO concentration did not exceed 1.5% in any case. DMSO was addedto all control wells at an appropriate concentration.

Following the addition of virus, cells were incubated at 37° C. in ahumidified, 5% CO₂ atmosphere for 7 days. Test compounds could be addedon days 0, 2 and 5 if desired. ON day 7, post-infection, the cells ineach well were resuspended and a 100 μl sample of each cell suspensionwas removed for assay. A 20 μL volume of a 5 mg/ml solution of3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) wasadded to each 100 μL cell suspension, and the cells were incubated for 4hours at 27° C. in a 5% CO₂ environment. During this incubation, MTT ismetabolically reduced by living cells resulting in the production in thecell of a colored formazan product. To each sample was added 100 μl of10% sodium dodecylsulfate in 0.01 N HCl to lyse the cells, and sampleswere incubated overnight. The absorbance at 590 nm was determined foreach sample using a Molecular Devices microplate reader. Absorbancevalues for each set of wells is compared to assess viral controlinfection, uninfected control cell response as well as test compound bycytotoxicity and antiviral efficacy.

TABLE 16 IC₅₀ EC₅₀ TD₅₀ Entry Compound (nm) (nm) (nm) 1

16 55 27 2

1 5 203 3

1 11 780 4

27 64 28 5

19 88 11 6

>100 380 425 7

3 25 39 8

85 1200 24 9

53 398 15 10

45 700 12 11

3 11 54 12

2 12 7.5 13

3 >16 14

4 15 55,000 15

5 38 16

9 80 62,000 17

4 5 59,000 18

4 19

8 20

4 21

73 22

15 18 31,000 23

2 24

3 25

60 120 167,000 26

27

5 177 300,000 28

14 76 213,000 29

5 105 196,000 30

6 154 154,000 31

10 32

5 98 17,000 33

18 68 34

67 188 35

18

The compounds of the present invention are effective antiviral compoundsand, in particular, are effective retroviral inhibitors as shown above.Thus, the subject compounds are effective HIV protease inhibitors. It iscontemplated that the subject compounds will also inhibit otherretroviruses such as other elentiviruses in particular other strains ofHIV, e.g. HIV-2, human T-cell leukemia virus, respiratory syncitialvirus, simia immunodeficiency virus, feline leukemia virus, felineimmuno-deficiency virus, hepadnavirus, cytomegalovirus and picornavirus.Thus, the subject compounds are effective in the treatment and/orproplylaxis of retroviral infections.

Compounds of the present invention can possess one or more asymmetriccarbon atoms and are thus capable of existing in the form of opticalisomers as well as in the form of racemic or nonracemic mixturesthereof. The optical isomers can be obtained by resolution of theracemic mixtures according to conventional processes, for example byformation of diastereoisomeric salts by treatment with an opticallyactive acid or base. Examples of appropriate acids are tartaric,diacetyltartaric, dibenzoyltartaric, ditoluoyltartaric andcamphorsulfonic acid and then separation of the mixture ofdiastereoisomers by crystallization followed by liberation of theoptically active bases from these salts. A different process forseparation of optical isomers involves the use of a chiralchromatography column optimally chosen to maximize the separation of theenantiomers. Still another available method involves synthesis ofcovalent diastereoisomeric molecules by reacting compounds of Formula Iwith an optically pure acid in an activated form or an optically pureisocyanate. The synthesized diastereoisomers can be separated byconventional means such as chromatography, distillation, crystallizationor sublimation, and then hydrolyzed to deliver the enantiomerically purecompound. The optically active compounds of Formula I can likewise beobtained by utilizing optically active starting materials. These isomersmay be in the form of a free acid, a free base, an ester or a salt.

The compounds of the present invention can be used in the form of saltsderived from inorganic or organic acids. These salts include but are notlimited to the following: acetate, adipate, alginate, citrate,aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, camphorate,camphorsulfonate, digluconate, cyclopentanepropionate, dodecylsulfate,ethanesulfonate, glucoheptanoate, glycerophosphate, hemisulfate,heptanoate, hexanoate, fumarate, hydrochloride, hydrobromide,hydroiodide, 2-hydroxy-ethanesulfonate, lactate, maleate,methanesulfonate, nicotinate, 2-naphthalenesulfonate, oxalate, palmoate,pectinate, persulfate, 3-phenylpropionate, picrate, pivalate,propionate, succinate, tartrate, thiocyanate, tosylate, mesylate andundecanoate. Also, the basic nitrogen-containing groups can bequaternized with such agents as lower alkyl halides, such as methyl,ethyl, propyl, and butyl chloride, bromides, and iodides; dialkylsulfates like dimethyl, diethyl, dibutyl, and diamyl sulfates, longchain halides such as decyl, lauryl, myristyl and stearyl chlorides,bromides and iodides, aralkyl halides like benzyl and phenethylbromides, and other. Water or oil-soluble or dispersible products arethereby obtained.

Examples of acids which may be employed to form pharmaceuticallyacceptable acid addition salts include such inorganic acids ashydrochloric acid, sulphuric acid and phosphoric acid and such organicacids as oxalic acid, maleic acid, succinic acid and citric acid. Otherexamples include salts with alkali metals or alkaline earth metals, suchas sodium, potassium, calcium or magnesium or with organic bases.

Total daily dose administered to a host in single or divided doses maybe in amounts, for example, from 0.001 to 10 mg/kg body weight daily andmore usually 0.01 to 1 mg. Dosage unit compositions may contain suchamounts of submultiples thereof to make up the daily dose.

The amount of active ingredient that may be combined with the carriermaterials to produce a single dosage form will vary depending upon thehost treated and the particular mode of administration.

The dosage regimen for treating a disease condition with the compoundsand/or compositions of this invention is selected in accordance with avariety of factors, including the type, age, weight, sex, diet andmedical condition of the patient, the severity of the disease, the routeof administration, pharmacological considerations such as the activity,efficacy, pharmacokinetic and toxicology profiles of the particularcompound employed, whether a drug delivery system is utilized andwhether the compound is administered as part of a drug combination.Thus, the dosage regimen actually employed may vary widely and thereforemay deviate from the preferred dosage regimen set forth above.

The compounds of the present invention may be administered orally,parenterally, by inhalation spray, rectally, or topically in dosage unitformulations containing conventional nontoxic pharmaceuticallyacceptable carriers, adjuvants, and vehicles as desired. Topicaladministration may also involve the use of transdermal administrationsuch as transdermal patches or iontophoresis devices. The termparenteral as used herein includes subcutaneous injections, intravenous,intramuscular, intrasternal injection, or infusion techniques.

Injectable preparations, for example, sterile injectable aqueous oroleaginous suspensions may be formulated according to the known artusing suitable dispersing or wetting agents and suspending agents. Thesterile injectable preparation may also be a sterile injectable solutionor suspension in a nontoxic parenterally acceptable diluent or solvent,for example, as a solution in 1,3-butanediol. Among the acceptablevehicles and solvents that may be employed are water, Ringer's solution,and isotonic sodium chloride solution. In addition, sterile, fixed oilsare conventionally employed as a solvent or suspending medium. For thispurpose any bland fixed oil may be employed including synthetic mono- ordiglycerides. In addition, fatty acids such as oleic acid find use inthe preparation of injectables.

Suppositories for rectal administration of the drug can be prepared bymixing the drug with a suitable nonirritating excipient such as cocoabutter and polyethylene glycols which are solid at ordinary temperaturesbut liquid at the rectal temperature and will therefore melt in therectum and release the drug.

Solid dosage forms for oral administration may include capsules,tablets, pills, powders, and granules. In such solid dosage forms, theactive compound may be admixed with at least one inert diluent such assucrose lactose or starch. Such dosage forms may also comprise, as innormal practice, additional substances other than inert diluents, e.g.,lubricating agents such as magnesium stearate. In the case of capsules,tablets, and pills, the dosage forms may also comprise buffering agents.Tablets and pills can additionally by prepared with enteric coatings.

Liquid dosage forms for oral administration may include pharmaceuticallyacceptable emulsions, solutions, suspensions, syrups, and elixirscontaining inert diluents commonly used in the art, such as water. Suchcompositions may also comprise adjuvants, such as wetting agents,emulsifying and suspending agents, and sweetening, flavoring, andperfuming agents.

While the compounds of the invention can be administered as the soleactive pharmaceutical agent, they can also be used in combination withone or more immunomodulators, antiviral agents or other antiinfectiveagents. For example, the compounds of the invention can be administeredin combination with AZT, DDI, DDC or with glucosidase inhibitors, suchas N-butyl-1-deoxynorjirimycin or prodrugs thereof, for the prophylaxisand/or treatment of AIDS. When administered as a combination, thetherapeutic agents can be formulated as separate compositions which aregiven at the same time or different times, or the therapeutic agents canbe given as a single composition.

The foregoing is merely illustrative of the invention and is notintended to limit the invention to the disclosed compounds. Variationsand changes which are obvious to one skilled in the art are intended tobe within the scope and nature of the invention which are defined in theappended claims.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

What is claimed is:
 1. Compound represented by the formula:

wherein: R represents 2-quinolinylcarbonyl; R¹ represents hydrogen andradicals as defined for R³ or R and R′ together with the nitrogen towhich they are attached represent heterocycloalkyl and heteroarylradical; R¹ represents hydrogen, —CH₂SO₂NH₂, —CH₂CO₂CH₃, —CO₂CH₃,—CONH₂, —CH₂C(O)NHCH₃, —C(CH₃)₂(SH), —C(CH₃)₂(SCH₃), —C(CH₃)₂(S[O]CH₃),—C(CH₃)₂(S[O]₂CH₃), alkyl, haloalkyl, alkenyl, alkynyl and cycloalkylradicals, and amino acid side chains selected from asparagine, S-methylcysteine and the sulfoxide (SO) and sulfone (SO₂) derivatives thereof,isoleucine, allo-isoleucine, alanine, leucine, tert-leucine,phenylalanine, ornithine, histidine, norleucine, glutamine, threonine,glycine, allo-threonine, serine, O-methyl serine, asparatic acid,beta-cyano alanine and valine side chains; R² represents alkyl, aryl,cycloalkyl, cycloalkylalkyl and aralkyl radicals, which radicals areoptionally substituted with a group selected from alkyl and halogenradials, —NO₂, —C=N, CF₃, —OR⁹, —SR⁹, wherein R⁹ represents hydrogen andalkyl radicals, and halogen radicals; R³ represents alkyl, haloalkyl,alkenyl, alkynyl, hydroxyalkyl, alkoxyalkyl, cycloalkyl,cycloalkylalkyl, heterocycloalkyl, heteroaryl, heterocycloalkylalkyl,aryl, aralkyl, heteroaralkyl, aminoalkyl and mono- and disubstitutedaminoalkyl radicals, wherein said substituents are selected from alkyl,aryl, aralkyl, cycloalkyl, cycloalkylalkyl, heteroaryl, heteroaralkyl,heterocycloalkyl, and heterocycloalkylalkyl radicals, or in the case ofa disubstituted aminoalkyl radical, said substituents along with thenitrogen atom to which they are attached, form a heterocycloalkyl or aheteroaryl radical; R⁴ represents radicals as defined by R³.
 2. Compoundof claim 1 wherein R¹ represents alkyl, alkynyl and alkenyl radicals,and amino acid side chains selected from the group consisting ofasparagine, valine, threonine, allo-threonine, isoleucine, S-methylcysteine and the sulfone and sulfoxide derivatives thereof, alanine, andallo-isoleucine.
 3. Compound of claim 1 wherein R¹ represents methyl,propargyl, t-butyl, isopropyl and sec-butyl radicals, and amino acidside chains selected from the group consisting of asparagine, valine,S-methyl cysteine, allo-iso-leucine, iso-leucine, threonine, serine,aspartic acid, beta-cyano alanine, and allo-threonine side chains. 4.Compound of claim 1 wherein R¹ represents propargyl and t-butylradicals.
 5. Compound of claim 1 wherein R¹ represents a t-butylradical.
 6. Compound of claim 1 wherein R¹ represents amino acid sidechains selected from asparagine, valine, alanine and isoleucine sidechains.
 7. Compound of claim 1 wherein R¹ represents amino acid sidechains selected from asparagine, iso-leucine and valine side chains. 8.Compound of claim 1 wherein R¹ represents an asparagine side chain. 9.Compound of claim 1 wherein R¹ represents a t-butyl radical and anasparagine side chain.
 10. Compound of claim 1 wherein R¹ represents apropargyl radical.
 11. Compound of claim 1 wherein R¹ represents anisoleucine side chain.
 12. Compound of claim 1 wherein R¹ represents avaline side chain.
 13. Compound of claim 1 wherein R² represents alkyl,cycloalkylalkyl and aralkyl radicals, which radicals are optionallysubstituted with halogen radicals and radicals represented by theformula —OR⁹ and —SR⁹ wherein R⁹ represents hydrogen and alkyl radicals.14. Compound of claim 1 wherein R² represents alkyl, cycloalkylalkyl andaralkyl radicals.
 15. Compound of claim 1 wherein R² represents aralkylradicals.
 16. Compound of claim 1 wherein R² represents CH₃SCH₂CH₂—,iso-butyl, n-butyl, benzyl, 4-fluorobenzyl, 2-naphthylmethyl andcyclohexylmethyl radicals.
 17. Compound of claim 1 wherein R² representsan n-butyl and iso-butyl radicals.
 18. Compound of claim 1 wherein R²represents benzyl, 4-fluorobenzyl and 2-naphthylmethyl radicals. 19.Compound of claim 1 wherein R² represents a cyclohexylmethyl radical.20. Compound of claim 1 wherein R³ and R⁴ independently represent alkyl,haloalkyl, alkenyl, alkoxyalkyl, cycloalkyl, cycloalkylalkyl,heterocycloalkyl, heterocycloalkylalkyl, aryl, aralkyl and heteroaralkylradicals.
 21. Compound of claim 20 wherein R⁴ represents phenyl. 22.Compound of claim 20 wherein R³ and R⁴ independently represent alkyl andalkenyl radicals.
 23. Compound of claim 20 wherein R³ and R⁴independently represent alkyl, alkenyl, haloalkyl, alkoxyalkyl andhydroxyalkyl radicals.
 24. Compound of claim 20 wherein R³ and R⁴independently represent alkyl, cycloalkyl and cycloalkylalkyl radicals.25. Compound of claim 20 wherein R³ and R⁴ independently representalkyl, heterocycloalkyl and heterocycloalkylalkyl radicals.
 26. Compoundof claim 20 wherein R³ and R⁴ independently represent alkyl, aryl andaralkyl radicals.
 27. Compound of claim 20 wherein R⁴ represents phenyland substituted phenyl radicals.
 28. Compound of claim 1 wherein R³represents alkyl radicals having from about 2 to about 5 carbon atoms.29. Compound of claim 1 wherein R³ represents n-pentyl, n-hexyl,n-propyl, i-butyl, cyclohexyl, neo-pentyl, i-amyl, and n-butyl radicals.30. Compound of claim 1 wherein R³ and R⁴ independently represent alkylradicals having from about 2 to about 5 carbon atoms, cycloalkylalkylradicals, aralkyl radicals, heterocycloalkylalkyl radicals orheteroaralkyl radicals.
 31. Compound of claim 1 wherein R³ representsisobutyl, n-propyl, n-butyl, isoamyl, cyclohexyl, cyclohexylmethylradicals and R⁴ represents phenyl and substituted phenyl radicals. 32.Compound of claim 1 wherein R³ is cyclohexylmethyl and R⁴ is phenyl andsubstituted phenyl radicals.
 33. Compound of claim 1 wherein R³ isi-amyl or i-butyl and R⁴ is phenyl or substituted phenyl selected frompara-chlorophenyl, para-fluorophenyl, para-nitrophenyl,para-aminophenyl, and para-methoxyphenyl.
 34. Compound of claim 1wherein R³ is i-butyl and R⁴ is phenyl.
 35. Compound of claim 1 whereinR³ is n-butyl and R⁴ is phenyl.
 36. Compound of claim 1 wherein R³ iscyclohexyl and R⁴ is phenyl or substituted phenyl selected frompara-chlorophenyl, para-fluorophenyl, para-nitrophenyl,para-aminophenyl, and para-methoxyphenol.
 37. Compound of claim 1wherein R⁴ represents alkyl and cycloalkyl radicals.
 38. Compound ofclaim 1 wherein R⁴ represents aryl radicals.
 39. Compound of claim 1wherein R⁴ represents heteroaryl radicals.
 40. Compound of claim 1wherein R³ represents heteroaralkyl radicals and R⁴ is phenyl orsubstituted phenyl selected from para-chlorophenyl, para-fluorophenyl,para-nitrophenyl, para-aminophenyl, and para-methoxyphenyl.
 41. Compoundof claim 1 wherein R³ is a p-fluorobenzyl radical and R⁴ is a phenylradical or substituted phenyl selected from para-chlorophenyl,para-fluorophenyl, para-nitrophenyl, para-aminophenyl, andpara-methoxyphenyl.
 42. Compound of claim 1 wherein R³ is a4-pyridylmethyl radical or its N-oxide and R⁴ is a phenyl radical orsubstituted phenyl selected from para-chlorophenyl, para-fluorophenyl,para-nitrophenyl, para-aminophenyl, and para-methoxyphenyl.
 43. Compoundof claim 1 wherein R⁴ represents an alkyl radical having from 1 to about6 carbon atoms.
 44. Compound of claim 1 wherein R⁴ represents a 5 or6-membered heterocyclyl radical, optionally substituted with an alkylradical having from 1 to about 3 carbon atoms.
 45. Compound of claim 1where R¹ represents the amino acid side chain of asparagine.
 46. Apharmaceutical composition comprising a compound of claim 1 and apharmaceutically acceptable carrier.
 47. Method of treating a retroviralinfection comprising administering an effective amount of a compositionof claim
 46. 48. Method of claim 47 wherein the retroviral infection isan HIV infection.
 49. Method for treating AIDS comprising administeringan effective amount of a composition of claim 46.